Larger stack size

[Dave Britten]

Was there ever any discussion within (or outside) HP about increasing the stack size, prior to the change to RPL with its effectively unlimited stack? In the TI-59/58 manual, "Personal Programming", they give the - admittedly contrived - example that can be evaluated left to right with that model's large AOS stack:

(((2x(2x(2x(2x(2x(2+2^(2+.2))-(2+2))))))/2)/2)

On my 58C, I can just plow through this left to right and come up with 36.76, whereas the 4-level RPN stack necessitates dissecting a formula like this and working from the inside out. There is definitely more thought required in evaluating this on a 15C, for example.

Did HP ever consider increasing the stack size beyond 4, or did they figure that mentally tracking that many parentheses and carrying out the pending operations manually is no more efficient/easy than working the equation inside out? I've never seen any mention of this in the PPC Journals I've read, but it seems like the sort of thing that would have been a useful salvo in the HP/TI wars.