Most of the Z wave switches are Spec’d for up to three in a box, but not four. For example, both Leviton and GE have instructions for triple gang boxes. You could write to them and ask if the same switches can work in a quadruple gang, but I’m guessing that since with each additional switch the wattage Max goes down that it probably runs too low.
There’s a nice looking alternative, but the problem is it’s not cheap, and that’s to use an individual in wall micro for each of the switches. @mike_maxwell combines Aeotec micros with Legrand retractive buttons, and I think they look really nice. There are lots of color options. But they aren’t cheap.
If you did go with smart bulbs, then it would be easy, there are several multi button battery operated wall switch devices that have four or more buttons. And if you just went with regular white smart bulbs, those are about $15 each, plus maybe $50 for the four button wall switch, so that’s probably the least expensive choice. But I do understand if you would rather get smart switches and dumb bulbs. I just wanted to mention the alternative.
Definitely check with Leviton, though, I think they’re the most likely to have a regular Z wave rocker switch that you could put in a four gang box. Let us know what you find out.