I thought eliminating a 4.5mm spacer to reduce spoke flange offset would be worthwhile, but 1x and 2x cranksets have largely wiped out 7-speed cassettes, making it less worthwhile to eliminate that 4.5mm spacer. A 7-speed, 12-14-16-18-22-28-34T cassette I got a couple of years ago is now out of production and its manufacturer offers only 11/12-28T 7-speed cassettes, a sign of retirement, about the same as what is available for 5-speed cassettes, barely enough gearing to keep them on the road.
However, that same manufacturer does make high capacity 7-speed freewheels, not freehubs but freewheels, as another option for reducing flange offset. BTW, I have put many thousands of miles on freewheels, which do work reliably well and are good, and maybe a slightly sidestepped 135mm 7-speed freewheel hub would work.
Truth be told, my bike runs on 8-speed chains, I like 8-speed components too and my 8/9/10-speed hub has less flange offset than the newer hubs. I will keep looking into a 7-speed freehub body conversion but not as a high priority. Yet I can not bring myself to give up on that idea completely as it is there to be done.