When I first open the settings screen it shows the ROM path.
I also searched for .ini files on the sd card but none of the ones that showed up were for the games
I'm using a DSTT and this worked for me as well. But I can only run the games by going through add games, they aren't added to the TWLoader menu for me to select when I open up TWloader
Not sure about other models of Pi4 but the Pi 4 B with 8GBs OCed to 2Ghz handles PSP really great except like 1 game I found and it is playable it just looks bad lol Motor Storm Arctic something or other.