IMO Boba's escape precludes the sarlacc from being able to contain a sith lord.

All canon/noncanon stories essentially have Boba blowing his way out with thermal detonators and/or subsequently being spat out.

I feel like the only reason that method of escape wouldn't be common knowledge is because of how rare sarlaccs are to begin with.

Genuinely considered Boba Fett's escape being the catalyst that sets the guy free. Could even retcon in that the only reason either worked was because of the other. Boba fett's bombs could only weaken it because of the psychic battle it was already in, sith guy won the psychic battle because the sarlacc was distracted by the bombs.

Could even capitalize on book of Boba fett by having fett play a reluctant hero role for the new cast, informing them of the sith guy's plans because they were both connected through the sarlacc so there was some bleed over.

If they're in the same sarlacc, maybe Boba only managed it because the sarlacc was currently weakened by the psychic battle with the sith lord. Who in turn capitalizes on the distraction caused by Boba to then escape himself.

Why? Palpatine needed to be in the last movie so Darth Vader could have a sudden yet inevitable change of heart that was tragically too late.

I didn't see the movie and for years I though it was a meme. An absurd one, too dumb to even be really funny.