I'd leave it on but skew it either forwards or backwards in the enclosure so there are areas away from it that stay warmer but have slightly less intense UVB exposure. Same for mounting it over the basking area and leaving a portion on the cool end to act as a shade area. As long as there are plenty of options, it should be fine.
Yeah, that's why I have a few hiding spots. The two areas to hide on the left away from the main heat source. also, while a baby, he can get under the basket on the right side. The fixtures are already screwed into position as well.
I, personally, would probably find a slightly shorter basking item. My dragons cave he pancakes out on is only about 4-5" tall, just enough for him wiggle under. I think 9" away with a reflector would be too strong. You can also provide something that's more diagonal instead (like a ramp to bask on instead of a flat horizontal surface), so if he want to stay warm but decrease his exposure he can shift downwards. The best thing really would be to get a Solarmeter so you can test and see exactly where everything needs to be and whether with or without the reflector is better. It takes all the guess work out.