Does anyone have experience with NSL (National Specialty Lighting) Low voltage puck lights under cabinet?

My cabinet's have been cut under the uppers for them to be installed but - my electrician can't figure out how to make them work with a wall switch/dimmer.

How we got to this point is along story... but the "reader's digest" version s that my upper cabinets have holes in a in a panel underneath the uppers for the puck lights. Prior to cabinet installation, the electrician ran all the wire required but should have collaborated with the GC and cabinet maker to make sure he could do what needed to be done - did not do that. Now the electrician is telling me they cannot be placed on a wall switch dimmer. I don't want to have to have new panels made nor do I want to have to dim each of my 20 lights from inside a cabinet.

Has anyone used the NSL under cabinet LV pucks?