I started collecting data on M100 about a year ago. Despite increasing integration time I was not quite satisfied with the outcome. It is just recently, with the arrival of a new galaxy season that I was able to add enough time.
To try to better resolve the core of M100, I added about 20h worth of 10s subframes. In total, I kept 55h out of 70h of data. I stacked this with Siril and 2x drizzle and post-processed with PI.
This is captured with a S50, so the outcome is still limited by the 2.4 arcsec/pixel resolution, but I was happy to see a little bit if detail emerge in the core.