I will be your savior and actually try it I have the PSN Symphony on my PS3.
Testing now...
No it doesn't work all the PS1 games must be 100% ports then. Im sure if they bring out a game that had the support back then like MGS 1.
Then it would work 100% of the time.
Also any game on PS2 from the actual PS1 game would have no chance of working all those games are bound to the actual settings that were implemented.
So if they built it with analog support then yes cause that game had analog back on PS1. If they built with only directional button support then no.