An electrician friend of mine showed me a trick a while back and I wonder if it would apply in this case. To help put in multi-gang switches, don’t tighten the switches to the box - keep it a bit lose. I can’t recall if one of the switch (maybe the center one) should be kept tighter…
From what I can see from the picture above, you could likely tighten them after the fact since access is available with the plate screwed in.