macOS guests?

[mrcalvin]

I am running as a host macOS 11 on an Intel MBP. I would like to run macOS guests, for example, to run and test some old 32 bit programs. Is it possible to setup an 10.14 guest using UTM? I fail to provide for an VM using an 10.14 ISO created via https://github.com/ninxsoft/Mist. The ISO is not recognised as bootable, I end up in the UEFI boot loader etc. I came across another discussion, but it remains opaque to me as whether there is an alternative (non-ISO) way?

Thx for a pointer!