Tail length doesn't affect furling much. Within reason a longer tail gives better stability. If the tail is too long you may have trouble keeping the moment low enough, but it is really the moment about the pivot that matters and reducing weight is better than reducing length.
You make it furl by leaving the tail anchored in space and it rotates about the yaw axis. You can make it crab at an angle to the wind if the tail is too short or too small but although it crabs, it may not furl.
I have a feeling that some of the burn outs have come from the mistaken belief that things are furling when in reality they are crabbing and running at a bit of an angle. It looks ok to see the tail at a bit of an angle in modest winds but to be sure, you have to see it swing its tail to about 60 deg to be absolutely sure things are furling.
If you can't get it to furl properly with a lighter tail then you may have the alternator offset too small. If it is below a critical value it will never furl.
If you are running at higher speeds up towards runaway instead of near stall it may need more offset.
Flux