Nathan,
Filters add about a third of their thickness to path length so it's really not worth adding if you use 2mm baaders.
I had my qhy9 setup like that, qhy9->nose->sx wheel->mpcc on a newt and it was fine. The mpcc needs 55mm. I used to plug a cheap orion oag into the wheel and used it with the RC8 and it was fine too.
I miss my 7 position wheel though, I'm waiting to find a decent lightweight alternative for 50mm filters
robin.