In the PC version, the 'random' offsets to the Random Number Lookup Table (RNLUT) increment even while the game is paused.
A random byte is accessed in this way at sub_5C8BA1 (decompiler output):
{
return b_RNLUT[byte_C06740[dword_C06738]++];
}
The c06740 and c06738 offsets increment in a simple way which attempts to point to a random number each time.
However, in the PSX version the offsets are frozen when the game is paused.
It turns out that both implementations can be abused (only useful in a TAS).
So, the mechanics were changed to have the randomness always running in-battle, even when paused, was this change intentional?
I don't know why they would make this change. I haven't seen any problem with the in-battle randomness in the PSX version.