We've been mulling this over for a good while now & a few folk said we wouldn't be able to accommodate all 3 disciplines . A few said don't bother with the hft element ( because of the things you mention ) to the comp but I would rather have not bothered with the it if we weren't allowing all to participate .
I know it'll be tricky to do hft style , but there's no reason why you can't walk the course first & make an educated guess on your parallax setting ( if adjustable ) before you shoot .
mr thorny croft , mi owd cock Sparra !
it'll be scored 1's n 0's .
Hope this helps .