I made a clean install of J 6.1.0 and successfully installed Delight (not kickstart).
I continued trying to install J2Commerce Pro.
Both downloadable versions failed to install and returned an error. (see attachments)
Version 4.0.20 is for J4 and 5 and 4.1.1 for J5 and 6.
It tried it with both enabling and disabling the compatibility plugin.
What are the perspectives.