Sorry, I had trouble registering at first, then we went away on vacation, and back only now...
I hadn't touched Secrets of the Sea level much, but that included indeed altering a little bit this pushblock puzzle, so as to add/use NG features and to use the block to activate a switch (which I considered so new and so cool in 2010 !!). I had missed that jumpswitch interference/issue, glad you found out and dealed with it early enough !
By the way, for Ship Graveyard level, I think the jellyfish comes from Teme9's amazing Nauticus object package. I also included some Base objects in Blue Alert level, and encourage you to see what could be interesting in the wad : https://www.trsearch.org/item/3557
Otherwise I had just had fun testing the brand-new-at-the-time fish emitter from TRNG !