The fuel drip discovery followed oil and filter change. I didn't notice any indication of fuel drip from the cover until it was time to leak check the screen and new filter. There was no leakage through the gasket between the throttle body and bowl and I couldn't readily see otherwise where it was coming from, so shut the fuel off and drained the gascolator, which seemed to stop what little flow there was. By then it was suppertime, and I let everything sit until the following afternoon when I could take the cover off and look further. The next day, with no indication of further fuel dripping, I ran the engine briefly for leak check, then removed the (dry) cover for a look-see. That being unproductive, and hoping it had somehow healed itself overnight, I cleaned the remnants of old RTV from the aforementioned gaps in the cover plate and resealed with Permatex fuel resistant Orange. Having left the fuel on during this entire time, there was no visible fuel leak down the venturi. Being suppertime again, I left the sealant to cure until the next afternoon. By then the drip had managed to re-establish itself, which brought me to my original question.
I agree that keeping dust out of the intake air, as much as possible, is desirable, but then so it is for remnants of sealant. Whoever last applied sealant had employed the "if a little is good, a lot is better" method, so there was plenty of the fuel degraded stuff dangling in the airstream. While I reapplied just enough sealant to do the job, I'm not fully convinced that the "fuel resistant" label is all it's cracked up to be. The gaps are few and small, so it's a matter of which is least harmful to enter the intake air flow, dust or a glob of RTV?
The fuel drip was very slow, not enough for a messy puddle in the air filter cover nor for any of the operational symptoms described. If it turns out to be a float issue, perhaps it hasn't yet reached that stage.