Some of interest, Air Dolomiti I believe is to restart the old Lufthansa FRA route this year. Lufthansa used to have a CRJ do the MUC route and an A319 do the FRA route which could be of interest. If Monarch had been given their 757’s those were a regular on the LGW/MAN routes to INN. Austrian Fokkers did some routes for a few years to UK and Irish destinations on ski charters but aside from that, nothing 757, Fokker and prop related in-game off the top of my head.
Air Berlin used to fly the Q400 in but we’re still yet to see the third highest voted airline 
, lots of 757 options irl but none yet in-game and likely not for a long time. Fokkers we’re missing the big charter operator Avanti which did a lot of flights in the late 2010s and in 2020. KLM might’ve done some limited charters with the Fokker 100 in the late 2000s but the records are a bit spotty for that.
If and when the 2010 limit gets pushed back and we get some 2000s airlines you could have DBA and GirJet, both of which did charters, the former for German ski tourists and the latter for Austrians heading to warmer Spanish shores. Spanair did some too with a mix of the Fokker 100s and MD’s.
If you fancy doing some realistic Fokker ops for AUA, I’ve got a fair few in the database thing here.
Glad you’re enjoying it though. Recently been enjoying BKK because I put the effort in to do realistic routes utilising aircraft types used or previously used and making a hodgepodge of A359/A346 line ups which surprisingly can keep me occupied for ages lol.