What I have noticed and the first thing to consider is whether or not the NDE involved any wicked or especially demonic spirits. Especially with demonic spirits, any interaction with them in the NDE after that seems to be corrupted, even if non-wicked/evil spirits are in it afterwards, because the demonic influence may make for extra ability for them to fake stuff and mislead the experiencer. At least some accounts seem to be blatantly influenced with demonic elements in the beginning of the experience to the end of it.
For example, in one experience the person was sucked into a black hole like manifestation and trapped there until he made some kind of deal (solving some kind of algorithm, not exactly knowing what the deal was), and everything after that part was New-Age deception (new age angels, creation being from the void of nothingness (a boring, featureless, awful place to be, instead of God's wonderfulness) instead of God Almighty, etc.).
In another example, an experiencer met dead relatives, went to a peaceful place, then the sky tore open and a big demon reached out and grabbed her. Everything after that was hell, seeing Judas still there, escaping from there and hearing a demon saying "Nooooo...!" (a trick to trick the experiencer further into believing it, everything from a demon should not be trusted at all and ignored completely), and then going to "Jesus," represented as a giant with bare feet and yellow, cracked tonenails that the experiencer was repulsed to kiss, and then being shown a vision of God in a form the experiencer could understand - a big, giant eye looking at and observing everything at once (i.e. an occult symbol) (and not actually doing anything but observing and watching everything by that vision).
Another thing to consider is that whether the NDE is heavenly or hellish isn't one-to-one correspondent to how the person lived their life before it happened. Righteous-living people can have hellish experiences that ignite a passion and zest of life afterwards, people who have done something/things serious and bad (e.g. a mafia hitman) can get heavenly NDE's that are profoundly transformative. Still others may get NDE's whose contents draw upon the righteousness and/or unrighteousness they have lived in life as a guidance to living more righteously or guidance for a new purpose in life beyond what they could know or find before, and these NDE's can have pleasant and/or unpleasant elements, usually seemingly to the aim of helping the individual as I indicated previously here, whether they have demonic influence or (possibly/hypothetically) not. I advise here though that any help from the demonic, specifically also to do with NDE's, is complete deception, whether or not there is any truth mixed in with the lies. None of anything from the demonic is good for the individual, misleading, corrupting, and damaging one whatever one tries to glean or think about it. The best thing to do is ignore the demonic and ask Jesus Christ of the Holy Trinity to cleanse one of any influence from it.
In still another example, an older man with a terminal brain tumor died, saw a being as a mandala of all human souls and, if I recall correctly, appearing as the buddha, Jesus, other religious figures, etc. and was shown that no human soul had any darkness in it at all, how ever evil - even Hitler's soul. The experiencer was brought to all kinds of places being made of crystal, gold, etc. After this experience he was healed of his brain tumor and was known as an encyclopedia of near death experiences. This is a strange one considering just how much he experienced (there may be a whole book or books on it; I haven't read them) and that he was - apparently or ostensibly - divinely healed, unless demons have the power to heal the sick, even a brain tumor, and even prevent death and extend life or resurrect the dead/dying. Elements of the experiencer's NDE seem to teach universal salvation and no religion in particular being wrong as long as they teach people to do good things (i.e. God not hating idolatry (i.e. Jesus not throwing a buddhist into the lake of fire because he did not believe in Him specifically), so long as people try to find God how every they can and truly believe in or at least just seek to do good) and other things seeming most likely to contradict scripture - unless the true scripture and true meaning of the true scriptures has been obscured by time and the corruption of man and mainstream Christianity. Still, it may have been God that healed the experiencer and there may have been elements of it that contradict scripture that were demonically influenced, I will need to / it will need to be scrutinize(d) it carefully to determine if this epic NDE was indeed a grand deception for the experiencer.
As well, many if not most NDE experiencers report various changes soon if not abruptly afterwards, including enhanced abilities and even new abilities, such as increased intelligence, radical changes in one's physical appearance (probably reflecting changes in one's personality and other things and thus how the body is responding and adapting to accomodate those things (the body really doesn't seem to be just a shell to be discarded and just containing the true spiritual self and nature (as is commonly reported in NDE's and some religions, which is probably a misunderstanding of the individual) but is actually a reflection of the person in ways not really well understood in modern times but by perhaps gut instinct) ), hearing the thoughts of others and telepathy, seeing spirit, even bi-location if that is a thing - basically lots of psychic stuff. This is somewhat telling if these things are unbiblical and especially if the NDE is tainted or influenced from the beginning by the demonic. If such is true, the NDE and any changes from it should, again, not be embraced but ignored and cleansed from one with requesting and hoping for cleansing from Jesus Christ of the Holy Trinity.
Ultimately, the bottom-line of NDE experiences seems to point to NDE's being shaped by a person's prior experiences in life in some ways - not whether they are heavenly or hellish but there being continuity from the point of death through the experience and then back to life. It seems that NDE's indicate not even death provides full, ultimate enlightenment of all truth there is, uncolored by past knowledge or beliefs or experiences. It seems omniscience is of the realm of God, even if NDE experiencers report having a sense of all-knowingness, and other spiritual beings being just as subject to not having full knowledge of everything as we are in life. As people on earth we are in one place at any given time on a journey through life, and the same seems to hold true as spirits. I can't say this last point contradicts scripture.