I create screenshots routinely to support users on the Google support forums. This problem is a significant impediment. I have to move the cursor around until it either appears, or I can find it.

I experimented with the Accessibility setting that allows a larger cursor. If that feature is enabled, the screenshot crosshair is somewhat easier to see, but the normal cursor is too big.

#CBC-RS/TC-watchlist

The problem could probably be solved by simply increasing the thickness of the crosshair cursor.

Pretty sure this is a dupe of another issue, but I can't find it.

Could it be this archived issue?
 crbug.com/638785  - Better mouse indication for Partial Screenshots

To me, it's still an issue, perhaps the approach mentioned in the above feature request is plausible -

2. Add something that will point to the mouse such as Enlarge-on-shake or MD-ripple effect.

i'll dup this one into my request from earlier in the year.