Hi, today (22nd Sept 2022) I downloaded the patch for v1.52, which seems to have patched and the game still runs fine.

I have also downloaded the files to patch from v1.52 to v1.6 - but when I try to launch this the installer tells me the patch is not relevant to his version of the game.

has anyone else encountered this?

There is already a thread on that.
https://www.gog.com/forum/cyberpunk_2077/v16_upgrade_not_working_offline_installer

Which game version exactly have you installed? You sure you have the 1.52? There has been some confusion related to the version numbering after patch 1.5.