Line A:
1.
♣A
2.
♥A
3.
♥2
4.
♦A
5.
♣K
6.
♥3 ruffed high (if they break, cash three spades ending in table, then run hearts if spades went 4-1)
If the
♥K is still out...
7.
♦2
8.
♥8 ruffed high
9.
♠J to Q
10.
♠T
Hearts.
This makes if hearts are 4-2 (king long) and spades 3-2 or if hearts are 3-3 or 4-2 (king short) with spades 4-1, and nothing rude in the minors.
Line B:
1.
♣A
2.
♣K
3.
♥A
4.
♥2 ruffed low (maybe club ruff is better?)
5.
♦A
6.
♦K
7.
♦ ruff low
8-12. High cross ruff
This needs diamonds to break 4-3 or 2=5 as well as nothing rude in either rounded suit. It'll also survive when diamonds are 5=2 with
♦Q dropping and spades being 3-2 (ruff two diamonds high using trumps to get back to hand). You'd also make when LHO is 4252. The other chance is that, after RHO overruffs a diamond and returns a trump, hearts go 33 or
♥K doubleton and spades are now 2-2.
Line B looks better than line A. There's probably another line that's better than either of them. However, both of them look better than the line in the OP
Had I followed the line in the OP, I'd probably ruff the diamond, overtake the trump and play the last trump:
-
AQT8
-
K2
6
4
J64
J
Hopefully LHO is now down to:
-
KJxx
-
?x
If he pitches a heart, we throw a club, play heart to Q, A and another heart. If he pitches a club, we throw a club, play heart to T, club K and guess if he has KJ9x(x) or KJxx. If he started with 5 hearts we exit H8, if he started with 4 hearts then we have a straight up 50:50 guess to exit
♥8 or
♥Q.