When 2.4 comes and I farm Coil2, anyone who joins my party will be required to have i110 and link two HA weapons or they get the boot and blacklist. Once my party fills, I will then go on to enjoy farming. I did this with great success on 2.2 and T5 farming. The checkbox the OP wants would just be convenient so that people who don't read the party finder can't join and waste my time in the first place - since I would just kick them out anyway when they fail to link a weapon to show proof of completion.

I sell runs, and this checkbox would really not do anything for me in terms of getting more sales. Something like 70%+ of merc runs are for repeat customers. So don't go throwing that out when you have no experience. Hey that gives me an idea - I want tools for creating a thread that only people who have certain in-game achievements can post in! Anything endgame related you must have T5/TitanX clear, and to comment on job balance you must have T9 clear!