I've looked at that strainer on my boat and wondered about it. I'm used to huge bronze (?) and glass things that were on my Albin, servicing a small four cylinder Yanmar.
I've cleaned the strainer a couple of times; I keep getting a gray, putty like substance in it. Yesterday, I watched it while the engine was running, things looked normal.
My only concern is that it doesn't look very strong. A hard bump might break the plastic cover. It's located in a position where one might bump it when changing the oil filer, or cleaning under the engine. I was aware of the location and was careful when changing my oil filter yesterday.
Tuglet is a fresh water boat most of the time. Had it in brackish water a couple of months ago.
Gene