Similar to Thomas' suggestion:
In the 3D window, hidden line mode, select the marquee tool, and then select the 'flat marquee' geometry (it defaults to a 3D volume). Drag the marquee around the portion of the drawing that you want, and do a Copy. Respond to the dialog with the entities/etc that you want.
Create a new independent detail window and paste there. Or paste wherever.
You will notice the common thread in all of these workarounds: the 3D view / isometric is not linked and you will have to repeat the steps if your model changes.
Linked, annotatable 3D views is a long-standing wish.
Karl
One of the forum moderators
AC 28 USA and earlier • macOS Sonoma 14.7.1, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB