That's right, generally. Some different settings might be needed for brand new coins in Orphan City mode (like Expiry 1, Queue 0, Scantime 1), but past that point all settings should be the same. If you have -I 12 --thread-concurrency 8192 for one scrypt coin, you'll have -I 12 for --thread-concurrency for any other scrypt coin.
Only thing that changes and MIGHT cause isssues would be difficulty with the coin/pool. Nothing that should crash the card, though, just maybe have extra rejects.
I do run my machines quite close to their limits so perhaps it is just the additional load of small blocks / more rejects from FTC that was causing it. Also, FTC was/is being attacked so that could cause subtle differences in the workload I guess.
Anyway, thanks for confirming what I thought re. scrypt is scrypt.
Kate.