It is true that back-ups are rarely used, but I look at it this way,
if a ATP player retired before the deadline, players who picked from that match would be allowed to pick somebody else, right? You can change your pick before the deadline for whatever reason. So having BU just allows the replacement if a player retires after the suicide deadline, if lets say his match is in the evening session, or even if he retires before the deadline, players don't have to post again, and maybe some wouldn't know in time anyway.
But lets wait for other opinions.
I would keep with the current rules, but I have 1 suggestion.
In weeks when there is one tournament with a 28 player field and one with a 32 player field, please take the bigger field automatically.
The game really doen´t make much sense if there are only 3 matches on a monday
I just checked the calender, first week like this is Buenos Aires(32) / Marseille(28) / Memphis(32). (Would still need the poll for the two 32)
But only Memphis is ATP 500, do you suggest that we take ATP500 over 250 automatically as well?
I remember last season, an ATP250 won the poll against ATP500 (could have been at the very mentioned week), so Filipo made it the voted tournament but ATP500 point distribution.
These rules could be applied to 5, up to 10 weeks at best.
My opinion is, I'd sill go with poll always.
Again, we need more opinions.