A lot of solid ones mentioned here. What I might add to those listed above would be a form of mind control/telekinesis. Something like mesmerism, basically being able to directly make your Lees more ticklish.
Another one would be fine control of electrokinesis. Tickling is just our nerves firing electric impulses to the brain. Being able to do this yourself with minute electrical signals would let you conceivably send tickle signals up every single nerve at the same time, as well as different patterns of nerves. If you could do this at range, its basically a direct ship variant of telekinetic tickling.
Hydrokinesis would be fun too, ever had someone hold your foot up to the jets in a pool, or spray a tickle spot with those water pik thingos?
Portals would be fun as well, set one up so the Lee is looking right at their own soles as you tickle, or various other tickle spots.
Self duplication would be fun as well, basically a gang tickle on demand.
Then of course there would be like a mutagenic sort of kinesis on others, kinda like how that one person in One Piece manifests hands everywhere... She figures regularly in anime tickle art lmao
I don't think there is a single power I couldn't think of a way to leverage for enhanced tickling tbh
