The “issue” would be having to use bridge pins to keep the strings at a correct distance from the lever. I know that Glenn Hill has used Lovelands and claims there have been no problems. Cunningham and Caswell have used bridge pins on some of theirs, and so presumably left room for levers, though I don’t know with what success.
Strings are closest to the breaking point in the treble so I’d not advise putting levers or blades up there even if you have them lower down. Often, in fact there is not enough room up there.
Personally I don’t see much use for levers on a wire harp since you will not be flipping them in the middle of a piece (probably!). I do have blades on one of mine, but that is because I tune that one to Cmaj and am too lazy to retune if the piece calls for a different key. Usually I just transpose.
I just sent some blades to a friend who wanted them since she often plays with a group and does not like telling them to “Wait a sec while I retune to this key.”
Still, if you have a wire harp with bridge pins, it would not hurt (much) to try. I think that Universal levers might be a better way to go than Camacs, Truitts or Lovelands. Cheaper too.
Biagio