HP48 vs HP50 solver

[JurgenRo]

I am currently re-reading Bill Wickes HP48 Insights books. I noticed that the numerical solver of the HP50 seems to have been downgraded compared to the HP48. Example:

1. if 'EQ' contains a list of equations {EQ1, EQ2, EQ3, ...}, these can be loaded from the solver in both machines, but only in the HP48 can these equations be “switched through” in the solver. In HP50 apparently only EQ1 is considered.

2.the HP48 solver can be modified by adding lists, so {' EQ1' {“A” <<' expression'>>} {'B' <<' expression'>>}} generates the usual solver menu plus the additional softkeys A (white on black) and B (black on white), with which the corresponding expressions can be executed. The HP50 seems to simply ignore these additional lists.

Is there any reason for this downgrade?