No, you will not learn a whole lot, very quickly, on a 12.0 m2 rig with a 580 cm mast.
Too big, too heavy, too hard to rig.
A 460 mast would be a bit too long for a sail with a 452 luff length, and a 460 mast will be too
stiiff as well.
Shorter masts have a lower IMCS bend ratio number, which means they bend more easily with less
A 430 mast with a base extension on 22 cm (452 cm) would seem about right, but I would bet the final setup would be more in the 456-458 cm range.
Does the sail have an adjustable top fitting?
If so, and you have a 460 mast, then you can adjust the top strap to make the sail work on a 460 cm
imcs 24-26 MAST.
Hope this helps,
Might want to head to a shop and see if they will lend you a used demo mast (a 430 and a 460) and rig the sail on both masts and have them give you an opinion on which works better in the sail. Just rig it in their parking lot or on some nearby grass. They may even help you and give you their opinion, hoping they can sell you the mast.