Is there a reason why the <1 was removed? Since pyproject.toml declares "wheel ~= 0.42", the specification in the Makefile is therefore intentional.

First, there is no py-wheel >= 1. Second, ~= 0.42 actually translates to >=0.42<0.43, which we cannot satisfy, so if you insist on blindly following what pyproject.toml says, this port should be marked BROKEN. Or we can just accept that upstream made a mistake.

FWIW, they also claim not to support py-setuptools 81.0.0...

Yes, I'm aware that there isn't currently no py-wheel >= 1. If py-wheel reaches version 1.0 at some point, these version specifications are always quite helpful for identifying problematic ports in advance and taking a closer look at them..

No, ~= 0.42 resolves to >= 0.42, == 0.* or, more simply put as >= 0.42<1.

~= 0.42.0 would resolve to >=0.42<0.43 and it can also be verified accordingly by setting wheel ~= 0.42.0 in pyproject.toml. After that, the port can no longer be built due unsatisfied version requirements of py-wheel.

See also Compatible release clauses.

It seems that the port can be built with newer py-setuptools without any problems if py-setuptools < 81.0.0 is removed in pyproject.toml. As for the runtime and the other features, the current maintainer would have to take a look at that, because I'm not very familiar with that port.