Possibly he does. But I don't believe for one minute that the shape of the earth prevents someone from being saved.
You never hear evangelists including a flat earth in their Gospel presentations - even the NT writers didn't do that.
Jesus never said "believe in a flat earth and you will have eternal life."
The shape of the earth is not mentioned, or hinted at, in the Lord's Prayer, the Nicene creed or Apostles' creed.
The first Christian confession of faith was "Jesus is Lord", not "the earth is flat".
I don't believe that anyone says to a non Christian, "You believe that you are a sinner and cannot get to heaven by yourself, you accept that Jesus was, and is, God and that he died for you, you want to confess your sins and ask God to help you and have a relationship with him? Great! Now confess that the earth is flat, and you are ready to be saved". If they ever did, they should go back to college.
Satan hates God, Jesus and any mention of the cross. It is by the name of Jesus that Satan is overcome/driven out - not by stating that the earth is flat/round. In the book of Job it was Satan who said to God, "of course Job praises you, you have blessed him. Take that away and see what happens." Satan could only afflict Job up to a point. He was not powerful on his own, he needed God's permission before he could do anything. He never tried to get Job to change his ideas about the shape of the earth - he tried to get Job to curse God for his suffering, then he would die.
The only way that Satan uses this issue is by tying Christians up in knots so that they forget to concentrate on what is important. To get Christians fighting each other, so we forget we are supposed to be fighting him; persuading Christians to waste their time, and energy, debating unimportant, pointless issues instead of spending that time in prayer, mission or taking the Gospel to others.
And - like all the other interesting but trivial and non salvation issues that are debated on this forum, in church meetings and elsewhere - it looks like he's succeeding.
Just think what could happen if every Christian on this forum spent even half an hour a day extra in prayer for the world/Ukraine/Israel/Gaza instead of writing long posts? I can guarantee that all these debates would still be here when, or if, we got back - but what might have changed in that time?