That may not be good enough since you still might get near IR leakage.
Check for other leaks too, e.g., aound filter wheels and filter trays, if you are using ZWO products for those. They are known to leak light like a sieve.
To do a test if it is your camera, remove the camera from the OTA assembly, and cap it with a metal cap (don't use plastic caps since they will leak IR). Take some dark frames. If the problem goes away, the rest of your assembly is leaking.
Chen
