Clamshell over deck drain on '23

[oldfielder]

I replaced deck drains this winter. Had problems with one spouting while under way last year. The other(port) never needed a plug. I'm wondering if a clamshell over the hole would be a good idea if the problem continues this year. I'm about to launch the boat and was thinking about being proactive.
The little blocks are still in place in front of the scups, but just didn't seem to cut it on the starboard side.
Anyone see a problem with the clamshell?