That might be possible. It depends how well you can detatch and re-mount the lens. On one of the Dissection Microscope threads there are some images that show about the same field of view that you have (yours looks about 4mmx3mm), maybe a bit bigger. A different M12 lens or spacee shoud get to what you want. You could mount that camera relatively easily onto a modified camera_platform on your microscope.
I think that someone has also made a version of the lens spacer like the low-cost optcs, but with the lens much closer to the Pi Camera for a bigger field of view.
Edit:
Wider field of view lens spacer for Pi Camera was from @biodotpe Flat Top Microscope | IIBM UC | Chile - #8 by biodotpe . I cannot see the field of view posted, but comparing with the standard spacer it must be a few millimetres.
Field Dissection Microscope, small field of view: First build - Field Dissection Microscope - #18 by Wacky from @Wacky