There’s also a lot to learn in @Frage’s implementation post where he uses clear PVC pipe for an enhanced waterproofness :
plus @mattgalic solution: https://www.aliexpress.com/item/33002197500.html
discovered here: DIY - budget - high amp waterproof connectors - #10 by mattgalic - Electronics (ESC, remote, batteries) - FOIL.zone
IMHO, the 2 best waterproof manufactured connector covers so far… 
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