I can't see a situation where there would be unlimited trades prior to the commencement of Round 3.
It would be a complete disaster, as each team would have different caps based on how successful their first 2 round were - let's face it, we'd all load up on low breakeven, high value players...
I honestly think that's about as likely as doing a complete restart - and they've already said they will continue as if there was a break between R2 and R3.
Obviously we started with 34 trades to cover 24 rounds worth of matches (extended to 26 rounds due to Origin byes). So a 20 round comp is just a 4 game deduction i.e. a loss of 1/6th.
You get 2 bonus trades per SOO bye, so they should be scrapped. To me that leaves 28 for 24 rounds, so a 20 round comp should be 23 or 24 trades.
I am completely happy if they keep Round 3 at 2 trades. They could be generous and make it a max 4 trade round due to extenuating circumstances (it is a bit like the fallout from a SOO round), and maybe make the total for the year 25 or 26 trades.
I haven't checked my team, but from memory I know I lose Watkins, and am sure there is some other carnage. The way I figure it, we all knew there was a chance we wouldn't even make it through Round 1. Then Round 2 (empty stadiums round) meant we knew it was likely the season would be suspended, just a question of when. If you selected players with more risky JS then that's just the choice you made.
In a crazy year, I'm sure good players will do just fine if it's kept to 2 trades and the total cut proportionately. Anything much more than that just rewards people who probably quit halfway through the comp anyway...