A few weeks ago we did a first Zwift race among some friends. It quickly became clear that our levels are totally not the same.
Is there some way we can make a friendly Zwift race in a way that it’s sort of “fair” for everybody?
Without having to cheat with your weight settings.
That way everybody get’s a fair chance of winning the trophy (yes, we have a trophy 
)
Races by definition are not friendly, they are competitive, the best man wins, maybe off of your previous attempt sort out a time handicap
You could try a timed handicap system where you set off at different times according to previous results.
I use Best Bike Split, with our zftp and weight values on the appropriate course to fudge a handicap/time delay for each rider in the club.
It works “ok”, but does just render everything into a time trial, rather than having any sort of dynamic racing between us.
Everyone create a new account, then use whatever weight you like as handicaps? This won’t affect your primary account.
Use bikes with handicap, MTB vs, gravel vs road.
Use height change to bring the advantage down. 200cm rider vs a 140cm rider going to be a big diffence on the flat. But the 200cm rider will still have a big advantage on the climb, assuming they are much stronger.