Can I DL the trial on ps5, play it , and then use my save once the ps4 version i bought shows up?
I'm guessing it will still use the same ps5 install, and just use the ps4 disc to validate when launching?
So following up on this,
I installed the trial and played about 4 hours, save file exists.
Received the PS4 copy today, inserted play disc, and went back to the Trial Tile on the PS5
In the lower right icon after hitting down, I clicked on the PS5 upgrade, it took me through a quick "Free" PS5 upgrade purchase and then simply removed the trial in the icon name, leaving it just PS5. There is still a tile when you insert the ps4 play disc but the copying is always set to "paused" , and you don't need to use that icon. Just use the PS5 icon and everything works, including the save.