And Locator is smart enough to know about all "features" of AJMP/ACALL instructions.

I abolished the "A"s long ago, while it (Keil) did catch them, you got an error and when you changed a few As to Ls that scooted the rest just enough so on the next build that another "A" was out of range and ......

So, my $0.10 worth: if your derivative has more than 2k of program memory, do not use ACALL or AJMP.
IMHO, those instructions are there for one purpose: to make it possible to squeeze a bit more out of the small memory derivatives. Indeed, the now discontinued 751 (I think I have the number right) did not support LCALL and LJMP because you did not need them.

Erik