Sorry Daryl, been away with work.
My main halyard is a pain in the **** - for the reasons you stated, the curve in the sail is too much to get up a stiff mast about half way up it gets very difficult.
It used to jump the track on the way up, so i had the boltrope padded at the sail head, it still does sometimes (plastic track) and because I had the boltrope padded that addes extra friction.
Basically it all doesnt work well, but, then I go sailing at brighlingsea which at anything other than high tide is mud heaven, the halyard has been a godsend.
I will be redoing it all over the winter, but I will retain the halyard - its BEST use is actually for recovery, main comes doen quick with no rolling, and with the zip luff jib we're derigged before everyone else has found a helper to roll - and it saves all the scuffs you get on the wing bars.
I suspect a 2:1 on the main halyard will make it work ok.