I think most of their signings are done, reason being we currently have 69 on contract, with 7 draft picks, that would bring the total to 78 players.
That puts the Bills with at 14 spots after the draft to get to 90, that is right in line with Historically the number of UDFA that they typically bring in.
Now they could likely add some more 1 year deals, but I think they will wait until after the draft and see what shakes out at this point.