I am a bit confused here, but most likely because all my experience is with Denney Kitfoxes. I agree with those who are reluctant to remove fittings screwed into fiberglass. But, isn't the drain fitting screwed into fiberglass?

While I had my first Model IV, I removed the finger strainers for each annual - nine years worth. In those tanks, there was a Reducing Bushing screwed into the fiberglass tank and the finger strainer was screwed into that. I would hold the bushing in a wrench and remove the finger strainer without disturbing the bushing to tank threads. Are the new tanks designed to have the finger strainer screwed directly into the fiberglass?

As a side note, I only found foreign material once in all those annual inspections. It consisted of fairly large chunks of rubber consistent with what you might expect after an overhaul of an avgas fuel dispensing set-up. Nothing that would cause a problem given the fuel strainers, but definitely a likely issue with only a fuel port at the exit from the tank.