One of my early 90mm EDF powered "F-16" by Starmax, I bought from HK, the good old days ($274-Aust) delivered back in 2010 came fully fitted out incl. LE slats connected with the tiny piddly push rods to the main flaps off 9g servos. What a joke, LOL.
No wonder they were coming down crashing like a bags of potatos, LOL.
The first upgrade improvement was to disconnect them (LEs) and sealing them off with the tape.
With these type and size of models I would find them totally useless, just another sales gimmick for fools to get impressed.

Still flying it after 12 years of regular action.

My favored flying site.

Falkon AOA.

Sealed off LE Slats.

Highly upgraded to 8S from the stock 6S.