i would buy new camera for my closeup and macro ( microscope objective and normal macro lens) and general photo ( holiday trip...)
I have Pentax K3II , Panasonic G9 and Sony a6100 and macro lens Pentax 100mm macro, Laowa 25mm macro and Oshiro 60mm macro ( some photos on www.antoniodesantis.it)
I use infinitiy Olympus 10x/0.25 and 20x/0.40 with Sony a6100 ( with Raynox DCR150 and 250), Laowa 25mm macro with Panasonic G9 and Pentax 100mm macro with Pentax K3 II.
Some years ago i used Fuji XT1 but Xtrans sensor, imho, eat a lot of detail... ( i print my photos in A3+ size and i love view at 100%)
New Xtrans sesnor are better than old sensor?
I used also Fuji XT100 (bayer sensor) and it has excellent detail at 100%.
About Canon M6 mark II: 32mpx are good boost respect 24mpx, i think...
Have questions about the equipment used for macro- or micro- photography? Post those questions in this forum.