I've been using Forth for 13 years on the 65c02, with programs up to 10,000 lines with interrupts serviced in high-level Forth while NMIs interrupted those ISRs for service in assembly, and I've never gotten anywhere near running out of space on either stack except with the rare error situation ...

First off, thank you for your thorough reply. Although I am not responding to all of your points, I did get a lot out of your post.

You can split the data stack from the return stack...
If you're going to be dealing primarily with 16-bit values or 24-bit values, you can define multiple parallel ...

After an almost 20 year hiatus, I've become re-enamored with the 6502 mainly due to André LaMothe's XGameStation project . So, I'm playing around writing some generic algorithms (linked lists, hashes, regexes, etc.) and I'm curious how others handle passing data to and from subroutines. I should ...