Critique My Mast Climb

[TopHat]

Hi,
Mast is 10 metre high, 250mm(approx) round aluminium section mast, on a junkette rig 25ft yacht. Free standing. Halyards are external.
Today, i attached the halyard block tackle on my harness, also using a "Prusik" knot on the pull line to my harness. Also with a "Klemheist" knot around the mast as a safety backup. This was satisfactory, but could be improved....

So im asking if another improved system that i thought of afterwards would have any problems....Hoist a block tackle to the top of the mast with the halyard, then cleating off the halyard & simply pulling myself up using a "Prusik" knot on the block tackle?, (again also with a safety klemheist around mast).
Anyone see any problems?

Im very comfortable with "Prusik" knots being a rockclimber & arborist in previous lives, but havent used block-tackle's very much.
Thanks for any replies.
Tophat.

Im thinking of using 16mm static abseiling rope in the block tackle.