Speaking of old Phil, here's a link:
https://www.shallowwatersailor.us/swsmanual/dovekie_manual.pdf
...to a manual for the old Eddy & Duff Dovkie, a Phil Bolger design built in some numbers, as an example of an atypical sprit-boomed leg-o-mutton which was meant to be reefed. The extreme rake of the mast was, if memory serves, meant to somewhat the mitigate the effect of shifting the center of effort forward as the sail was reefed.
It's worth noting that Dovkie's sail was normally meant to be furled by rolling the fully hoisted sail into the mast by a sort of crank handle inserted along the lower bit of the leech, even though the sail was equipped with a halyard and could be fully lowered, as well. Quick and tidy, it was said by devotees of those boats. Small sails like this in working boats were typcally furled by rolling up the spirt and sail into the mast in similar fashion, making a tidy bundle which could be unshipped and laid down in the boat, probably hanging over a bit one way or the other.
I sometimes used to employ a similar technique, minus the crank, on my Sea Pearl 21 cat ketch, whose sails were loose footed (though not with sprit booms in the common Bermudan rig) and were fitted to the masts with luff pocket and could not, as a result, be lowered quickly. (Sails were normally furled by rolling up around the rotating masts.)
Anyway, inspired by Bolger's remarks about his Dovkie, I tried it out one time when I had landed on a beach and was anxious to get the sails furled quickly for some reason. I released the quick-release shackles at the clew, grabbed the leech, pulled down and back, and started to roll, securing the sail with a tight tie as far up the mast as I could reach. It was so effective that I dubbed it the "Bolger Quick Pearl Furl" and subsequently used it in situations where I wanted furl the sails quickly for short periods of time.
Dovkie notwithstanding, Laszlo's correct: these sprit-boomed, leg-o-mutton sails were typically used in small boats and were rarely intended to be reefed. The one case of these sails being used in larger craft that comes immediately to mind is the cat-ketch rigged sharpies. Those were typcially arranged so that, if the wind increased, either the main (foresail) or mizzen could be stepped in an extra mast step and partners arranged more amidships, so no reefing of those, either.
.....Michael