Safety or gamble at MP?

Saturday I played a marathon as preparation for the upcoming EK for university students. Concentration for a long period of time could be one of the biggest problems we'll face, so we played in a good field for an entire day with MP scoring. Imp tournaments are more relaxed imo, so MP is a great training.
We didn't do great, but it wasn't bad either. Some silly mistakes mainly in carding, but our bidding system and competitive agreements work.

The most interesting hand I declared was the following:
♠ AQ9x
♥ AQxxxx
♦ Axx
♣ -

♠ KT8x
♥ K
♦ KJx
♣ AJTxx

We were on the way to grand slam, but partner missed in number of keycards (it was late), so we ended up in 6♠ instead of 7. Not that it's such a great grand slam anyway, so I didn't complain (it would probably make, but that's not the important issue imo).

LHO leads ♣K. Imo the best way to make lots of tricks is to play on ♥s. I discard a ♦ in dummy and take my ♣A. Now comes ♥K of course, followed by a ♠ to the Ace. When you play a small ♥ RHO shows out (doesn't ruff ofcourse, since that's pointless).

Back into the tank! Is there still a way for +1? Is my contract in danger?

Trumps are 3-2 or 4-1. 3-2 is no problem. So what about 4-1? If RHO has 4 ♠s we'll probably go down. If LHO has 4 of them, we need to unblock ♠s when ruffing out our ♥s, and take the ♠ finesse later on to keep control of the hand. That's a safe line when LHO has 4♠s, but may still be dangerous if LHO has 3 ♠s and a singleton minor! We will have played ♦A to ruff a ♥...

Anyway, I choose to unblock the ♠s, ruffing with ♠T and ♠K (keeping ♠8 opposite ♠Q9x). When I played ♠8, LHO played the ♠J and I made +1.

I was quite surprized that scored a top! Since 6♠ is a normal contract, and ♠ are divided Jx-xxx, any line you choose will get you an overtrick as long as you play on ♥. LHO didn't have a singleton ♦, so the lead doesn't matter much. EXCEPT: the lead of a small ♠ will make it harder on you, because they take away an easy entry for ruffing out the ♥s. I guess you'll need even better unblocking there, and you'll need to play on a 3-2 split for sure. Still, you can always make the contract.