How can a remote computer screen accessed via screen sharing take over the entire desktop without any scaling (or perhaps 2:1 scaling only)?

I have an iMac 5K and a M1 MB Air. MB Air supports exactly half the resolution of the 5K (2560x1600). I use multiple spaces on the iMac5k. I want an entire full screen space to host the remote computer screen, with NO DECORATION from the iMac. No menubar. Not, 'auto hide', NO menubar. If I want to control the iMac, I would use a 3 finger pan to go back to another space. It seems to me this should be the simplest, default method. Without this, you either get a small non-scaled screen, or a scaled screen that is blurry and doesn't use the entire width of the display, or adds scroll bars - none of which is a practical solution. How can I do this with Apple Screen Sharing?