Hadn't tried it this way, thank you. Perhaps for clarity a new item called "folder" which doesn't contain roms but only consoles, would maintain it tidier.
Related to the tree structure, there's a suggestion for the searches. Currently AFAIK searches are done insde a console. Would be great to do the search on a "folder" containing multiple consoles, and then the results contain all the matches on all the consoles (i.e. searching "metroid" and finding all the metroid games on all the platforms).
Going one step ahead, then a search could be saved as a "playlist", and even be dynamic, and update when adding new "roms".