KS has a weight limit of 90kg for some of their posts but I can’t tell if the others have no limit or if it’s just not obvious. For whatever it’s worth for you guys, I had a KS totally rebuilt with new piston for £75- not cheap but probably worth it especially with a Lev.
Reverb isn’t that reliable but doesn’t really seem to be weight dependant, or really anything dependent- sometimes they work, sometimes they break.
Gravity Dropper is a really simple mechnical design and very reliable but a heavier rider will wear the plastic bushes faster so it’ll develop play quicker and need a service sooner. Pretty easy to do and the parts aren’t expensive, if you can still get them in the UK…