These points contradict. You say you bid 3♣ wanting to find the 5-3 club fit when partner is 1453, but then you say 3♣ is 4sF which may be based on Qxxxx Kxx Kx xxx. So if opener has 1453 then he bids 3NT and what does responder do with the current 5215? What if opener bid 3NT based on 2452? Or what if it's 0454 and opener may not be able to afford to bid over 3NT? What do you mean? If you bid 2♠ you're showing 5spades then opener can bid 2NT/3♣/3♦/3♥/3♠ naturally, ergo, patterning out. I personally believe 2♠ is the right bid if you have that agreement. Q98xx is considered a good enough suit that may warrant to play in 4♠ on a 5-3 fit. Like gnasher said, if 3♣ is 4sGF then on the auction that was given 3♠ can be based on 2452.