I would not release the mainsheet, on the Tiger we sheet in hard and then set the traveller halfway,
completely uncleat the cunningham and leave a little tension on the jib.
Then slowly push the rudders into the corner and leave them there.

With a Hobie training last year we practiced backing-up.
On a small course we would sail to the windward mark and from there backup all the way to the leeward mark.
(Sounds easier than it is).