I have a Mack Pack, but pretty similar.
My main sail is pretty new, and pretty stiff. I have to stuff it into my bag, but a few things can help…
1) if you have lazy jacks, keep them fairly tight when dropping the sail. For me, it seems channel the sail into the slot in the bag, so it doesn’t fall out on either side.
2) make sure the sail slides and sail track are clean and lubricated. I have a Tides Marine track, so it is pretty slippery. Having the slides and track clean and lubricated will help the sail fall faster and more completely, getting more in the bag on the drop.
3) On my set up, the slot in the bag is pretty tight right at the mast (not sure if the Doyle is the same). If I loosen the bad where it attaches to the mast (at least the top 2 snaps), the sail gets deeper in the bag without the need to stuff it dow.
The convenience of the bag and lazy jacks is priceless to me. I usually drop my main and get into the bag before heading into the marina. With the boat on AP, I can have sail in the bag, zipped up, halyard secured, traveller pulled to the side and have the boat ready to leave in her slip before I get back into the marina.
Good luck,
Greg