Any kind of multi-variant tournament or single-variant tournament would be
of interest to me. More than one could feasibly be in play at once. Game
courrier tends to encourage fast play, so this opens more options.
For scoring, there is no way to determine a fair score differential for
Black. FIDE is the only variant where a deecnt guess of the size of
White's advantage is available, and even that no doubt varies by rating.
Not all variants even favor the player who moves first--my own Pocket
Mutation Chess slightly favors Black under the current rules.