Yes I would expect that normal tape-to-tape copying would still work for this system, else the original software duplication-houses etc. would have required special equipment to do Commodore tapes.
And IIRC, there were some cassettes with Commodore on one side and another computer systems on the other. Or maybe those bargain compilation C90's etc. cassettes with lots of different formats on.
There was also the BASICODE (I have some cassettes for this, that I think were produced by the BBC / Radio 4 transmitted these?) system, where once you'd loaded the computer-specific interpreter, the BASICODE program cassettes would then load on any platform that supported BASICODE.
In terms of preserving original recording, I think this is best done using a digital format file, that can be stored on any media / 'net, rather than just creating more analogue cassette backups.
And ideally produced digitally, by re-saving the program from the PET, rather than trying to convert old cassettes in case these have faults.
But may need a bit of extra circuitry from the PET's cassette port digital output to the line input of a PC, to capture in audacity etc.
However, there are a few Commodore cassette interface replacements, based around the Arduino-nano microcontroller that use a memory card and have a small OLED screen to be able to load (and save I believe) tape files. I do have one of these that's nearly complete, that a friend who was getting his own customised PCB's made for these had given me. These were for the C64/VIC20, but I assume would also work with the PET:
https://www.c64-wiki.com/wiki/Tapuino_C64
I do recall various Spectrum add-ons that tried to 'regenerate' the audio signal, by feeding through digital gates with an in and out connection.
Or the Maplin 'Easy saver / loader' analogue filtering unit I once built (but stripped-down, as I don't recall it really worked that well)