A small not e about regional only sets you will have missing games due to some games only having a single regional release because there are PAL and NTSC exclusive games, you will also get the odd Japanese exclusive game that has has 3rd party translations
You could also make a request about stuff like this in our uploads section and I am sure it has been talked about before
Or even just a set with a copy of every english game no matter the region of the game without dupes
Getting a full No-Intro set that does not include hacks ect anyway can also be dat filtered by going to no-intro and making a custom dat to only include what you are asking for, a single region set with just english games included or other custom setup
The Custom No-intro dat shown in the screen grab that you create at there site is for the SNES set, it will still include re-releases e.g. v1 and v2 but otherwise it will not include any clones from other regions and only includes games with the english language in them, no unlicensed games and no pirate versions