In general, i think a lot of the percieved antagonism is just that..percieved. I dont think 99% of motorists care if we filter...most of us do it carefully.
This is true of most poor cycling behaviour. I drove into town last night in the dark. Two Polish (i assume) guys were riding along in the rush hour traffic with no lights...and holding some cars up. Did anyone appear to get agitated ?...no. They waited until a gap opened, then overtook the cyclists.
The irony is, i got more angry than the motorists appeared to be around me. Why ? because i feel their behaviour impacts on 'us'. But no-one else seemed bothered. Its percieved by me..but not apparently by other motorists
For every action you take, you will meet with mostly indifference from motorists, some (a small percentage) will accomodate you (like the drivers who hold back, as they should, and let you do your thing), and some (still a small percentage) will rage at you for doing the right thing, and sometimes the wrong thing.
There's no magic bullet...do your thing and do it safely as you can. Inevitably you will upset some, and you'll meet the occasional accomodating motorist.
I've always thought if anyone did remonstrate with me for filtering...my reply would be 'you wouldnt think twice if a motorbike did that...what's the difference ?'....as well as 'if you dont like sitting there..get a bike mate'
Ultimately, my point is, there is a lot of talk of cyclists alienating themselves from motorists. But my experience, and watching other cyclists much worse behaviour....is that motorists never appear that bothered.