Yes, I have the portable.dat file in the CCleaner directory. I have noticed this registry creating bug for portable since the 565 version, haven't noticed it in the 553 version.
I have been using CCleaner Portable for a long time now. I have noticed CCleaner Portable has started storing registry entries even though its portable. Could you please fix this.
The portable version I use is from the official website https://download.ccleaner.com/portable/ccsetup569.zip and this is the registry entry stored by it [HKEY_LOCAL_MACHINE\SOFTWARE\Piriform\CCleaner]