We did a camp knife challenge as the first one. It's possible a second one can be done...... We did a machete/chopper, but a heavier chopper could be fun.
So far what has been done through WSS is:
camp knife challenge (no specific blade limits, most were in the 6-10 inch range, IIRC)
machete challenge (this ended up including some more or less chopper aspects)
bushcraft knife challenge
necker challenge.
Personally, I'd like to see a camp kitchen challenge. It's not a "solo bushcraft" sort of thing, but anyone who ever has done a bush bash, hunting camp, family camp, scouting, or any other wilderness activity involving groups knows how big a deal this one can be- and how it can vary from "home cookin"
Not specifically realted to WSS, a nice, broad, multitester "EDC fixed blade" challenge with more common daily tasks could be a lot of fun and open things up to some different design ideas. Might be necessary to specify an urban/country focus. In relation tot hat, a "ranch/farm" EDC challenge could be cool as a separate entity.
An EDC challenge *could* open things up broader, move out of WSS specifically and operate as a much longer term thing, which would require some major dedication in terms of someone keeping track of things.
A KSA challenge (knife shaped axe- heavy chopper) could be cool, but we'd have to look at a specific testing range- is it like competition chopping? felling a 6 inch tree and making firewood?