I removed mine and so far have not missed it. Good idea? I don't know.
Random thoughts...comments please.
I suppose a pilot could run enough fuel into a horizontal intake sump to liquid lock a cylinder during start. Anybody ever heard of it happening?
The above may be only a taildragger issue, as I suspect fuel would run out the intake on an A-model before it got very deep in the sump plenum. Of course if the the airplane had a Vans snorkel from the left cowl intake and no drain hole....
It would seem like you should have a sniffle on a high wing airplane that can gravity feed fuel through a bad fuel valve/fuel servo/etc. That's not pilot error.
FWIW, the Lyc angle valve parts manual only lists a sniffle on two models with the common 74384 horizontal intake sump, A1B6 and A1D6. It lists four 1/8NPT plugs for the A2B, with a note "Assemble in fuel drain bosses in sump". Other models don't specify anything.
A good pressure recovery intake might open the check valve in flight. Sump plenum pressure should be higher than ambient, for sure if the sniffle drain line is plumbed to a static pressure point outside the cowl. Result would be a small manifold pressure loss and mixture tending rich. Both would be minor, but....