All electrical connections on Alchemy get a coating, before assembly, of a product called KoprCoat, a conductive copper-based paste. This includes, especially for outside connections, spreading out the wire strands and brushing them with KoprCoat (or the like), prior to their being twirled together and crimped into the terminal.This pretty much prevents water migration up the wire strands were water to intrude.
I have pretty much given up heat-shrink wrapping (people who use them all the time make them work, but, as an occasional user, I always messed it up: chose the wrong size or over-heated the wrap, etc.) and I have an alternative which works better for me.
It is a 3M product (130C) called Linerless Rubber Splicing Tape. It is a very stretchy self-amalgamating tape and what makes it work (unlike the disappointment with other self-amalgamating tapes, is that it also has an adhesive coating: together the covering fuses itself together in a way that has never failed me.
Between the two, my outside connections have stayed pristine when years later, I had occasion to take them apart.
I hope that helps: come back with questions.
My best, Dick Stevenson, s/v Alchemy