I wonder how Symphony of the Night 64 would have been.
Even Gamecom was going to have a SOTN port.
It would probably have been pretty bad, at least in performance terms. Moving around large 2D bitmaps is something that the N64 was not at all good at because it hammed the memory subsystem. The N64 had 4MB of unified memory and the old Rambus memory it used could only have a single page open at once - rendering large bitmaps resulted in a lot of memory accesses:
Read cart, decompress -> main memory
Read main memory -> frame buffer
Read frame buffer -> display
This is significant because a page miss (especially on Rambus) really kills performance - you have to close the existing page, put the chip into precharge mode, then send the page address, then the address in page and finally start the read cycle and transfer the data. So if you have a whole bunch of transfers going on at once and you end up page thrashing you lose most of the performance of the memory.
The other consideration is political - Nintendo have been known to refuse approval for games they think make their systems look bad - and a seriously degraded frame rate version of a game that ran smoothly on PS1 might well be considered to be in that category.