Since he doesn’t remember getting out of the sarlac in his armor, maybe don’t show that part? You could cut away after he uses his flame thrower inside the sarlac or start with him disoriented, being found by the Sand People.
I thought the same thing. The full Sarlacc escape could be placed somewhere later or as a post credit scene. We could follow the journey of the armor. If I remember correctly, Cobb Vanth tells the story of how he got the armor in his own flashback. I wonder if there will be a flashback where Boba Fett learns that Cobb has his armor, which would help.
EDIT: This is a bit off topic, but Boba Fett wanted to stay undercover and pretend he was still dead. I wonder if he ended up hearing about Boba Fett killing a krayt dragon, which is actually Cobb Vanth in his armor.