All, thanks for the replies. Spyder, your addons are incredible and I can't play without them now - and cheers to HeroesandvillainsOS for recommending them! The script works flawlessly too, absolutely what I was after.
Re: the persistence issue, I do all the right stuff for the markers to save (ctrl click, persistence on in modules etc.,) but it seems they just don't for some reason. Logistics is a bit temperamental too. Not sure if I'm just not giving it time to load in (running test missions at the moment that last for a few minutes just to check everything is working as it should). What's the best way to debug this? Past a copy of the logs?