So far, so good
I eliminated the external filter on my MBX7. Re-routed the fuel line to the hot side of the chassis because it was less of a hassle and keeps the fuel supply line short.
Caveat-I no longer race, so for me, dust on the track is w-a-y down. I only do test sessions where there are 1, maybe 2 other cars on the track. I think running an external filter is still a good thing to do-if you can find the room for the fuel supply line and it doesn't foul the carb or brake linkage.
-AC-