So I tested with the latest menu build. Pirates! easyflash seemed to work fine in both slot 3 and 4. Did saves, exited the game and updated the easyflash. It all seemed to work just fine.
However, when I tried Soul Force easyflash the first problem I encountered was on the game menu. I entered options and changed difficulty to easy and turned on autofire. As soon as I hit exit back to the main menu the game locked up. I think the game is supposed to save the settings at this point. Tried several times. Even resetting my TC64V2. Same thing happened.
Next, I tried the cracked excess easyflash version of soul force. This time it went fine going back to the main menu after changing the above mentioned settings. However, after I finished level 1 the game locked up. Again, it's supposed to save the game progress at this point. For soul force I only tested using slot 4. This is clearly an issue. And at this point I have not tested with more games.
Edit: oh, and if I hit TC64s menu button after soul force locked up it asks if I want to update the image. Naturally, because soul force easyflash locked up at the point where it saves settings or game progress