I did this for a couple years with my friends and it worked pretty well, though they have busy jobs and kids or some crap excuse this year.

Draft QB/RB/RB/WR/WR/WR/TE/FLEX (in any order). No K/DEF, no bench. You get your players' total points (PPR or whatever the consensus is), whether they play 4 games or 1.

6 owners seems optimal, though we can go a bit higher or lower. Winner-takes-all or 2nd gets their money back. We usually played $100/man.

To my knowledge, no site offers something like this, so we would just draft on a Google Sheet.

Has anyone done something similar, or would be interested in playing this year?

In the past, I've run (and others, too) something similar. Instead of specifying 2RB, 3WR, we did something like, 1QB, 1RB, 1WR, 1TE, 4Flex, D, K. Worked well, but we didn't have enough interest last year. Ran it on MFL, but it's a super-busy site.

For the AAF, I ran a 6-team league on a site, but did audits in a Google sheet. I reached out to the AltSports dude to see if he'd host something NFL. His site was raw, but easy to use.

My league does the playoffs without specific positions. Otherwise it's tough because in a 12-team league it almost becomes too structured since there are finite players available at QB/K/D and pretty much at TE too. Total points for the entirety of the playoffs, pay top 3 of 12. Of course our regular season is based on total points too.

Some guys go into it with a strategy to take a bunch of kickers since they're basically guaranteed points. Others load up on 2 or 3 teams. Some go specifically for players that don't have byes, others specifically for players that do have byes. It's really fun but so hard! I can remember games in the past that completely killed me. Green Bay/Dallas a few years ago when Rodgers came back with the pass to the TE on the sideline. Kansas City/Tennessee when the Chiefs inexplicably lost.

One of those teams that we like as a best bet team entering the 2020 NFL season is the Baltimore Ravens. The team rolled to a 14-2 record during the regular season while winning 12 straight games to end the regular season.