I downloaded and did an initial test of RC2 and it appears to work with EasyLayouts for Joomla 4. EasyLayouts works with J2Store by placing the shortcodes from https://docs.j2store.org/catalog/short-codes
in the structured layout and these appear to still work ok out of the box so you can create sophisticated article/product pages and include the J2Store elements you want in the positions you want them to appear.
Remember you would need to disable auto display of the cart if you want full control from within EasyLayouts
There may be further enhancements we could incorporate - if you had suggestions they would be very welcome.