Hi there,
I'm an active player in this server and I have to say farming mementos is hard nowadays 'cause there aren't that much people want to farm it.
As my friend says they were doing like 10-15 Grotto of Horrors runs per day 2 or 3 months ago, it seems easy and collectible for those days but these days. 10 Runs per day means 20-25 days to get Resplendent Ironblood Duke title, without that, 1 run per day is 200-250 days to get it or even without anything but siege war, its like 240-280 days to get.
My suggestion is trading badges with other sources, maybe Mirror Shard, or making it farmable solo, maybe adding some badge packs to wheel of fortune, I don't know. I don't want you make it easier to get, Im just asking if making mementos/badges possible to farm solo with same effort as farming on GoH instead of finding bunch of people who isn't able to find nowadays.
Thanks for any answer, have a good day.