Use frame as background

Hello,

I want to render an animation, say till frame 1000. Then, the current situation (i.e. Frame 1000) should be used as background for an ongoing animation.

I can achieve this manually by putting a plane in the background which contains the pre-rendered frame 1000. But if I change my animation before frame 1000, then the background image will not have updated.

Therefore my question: can I achieve it automatically that frame 1000 freezes and from then on is the background image.

Hope this makes sense

Is it possible to automate this? Probably. Is it a hassle and would I recommend just doing the solution you mentioned…yes. It will save time in the end over figuring out some complex workaround