Some brilliant work here. The documentation regarding time-sensitive wild encounters does seem to be a little out of date (or inaccurate? - either way, I was running into compile errors when following the instructions there), but the examples provided in the source were incredibly helpful in figuring that out.
However, I'm running into the same issue as another where the Wild Pokemon data is a completely garbled mess of characters in AdvanceMap 1.92. In 1.95 it's a similar story, only instead the entries are all completely empty. I followed the Recommended Insertion steps, including DPE, Sideways Stairs, Squeetz' music base, and the B/W menu, in case any of that might bust things a bit. I'll give it another go from scratch next time I can, might've flubbed a step somewhere, but I still figured it was worth mentioning here in any case.
EDIT: I probably should've verified that it was actually working with the unmodified Fire Red ROM to begin with, seems like it's just an issue with AdvanceMap being run in a Japanese locale. I apologize for the unnecessary report, wild data displays fine with the modified ROM running AdvanceMap in an English locale, though the Pokemon entries are missing completely. Everything seems to be in order now.
Thanks much to all whose contributions and efforts have went into this, it's really awesome to see.