Tatar can get you more

We aren't trading Tatar without a guaranteed 1st round pick. Maybe guaranteed 1st + another 1st if one of both of those conditions are met.

make the 2021 pick unconditional and the 2022 pick conditional on his re-signing.

Yup, no question. GMs and NHL staff know that he's worth a 1st rounder. He was worth a 1st, 2nd and 3rd before having 2 consecutive breakout years, brings tons of energy, still very young.
The only people who think he's worth less than a 1st are people who've never watched him play, have not watched him the last 2 years, know very little about the NHL market, or... and that's a big one, Hab-haters who constantly put down Habs players.