Thank you for the very interesting pointers.
In the course of the update to Qubes 4.2 and in the face of whonix-16’s approaching obsolescence I had switched sys-whonix to the testing template whonix-gateway-17. qubes-update-proxy was indeed not enabled, which is remedied now. It’s unclear whether this was an oversight of the upgrade process or whether this was alreadz broken in 4.1.
Additionally, tinyproxy in whonix-gateway-17-derived appVMs appear to have an issue to start the (enabled) service. systemctl status tinyproxy reports the process dead, as the start condition ConditionPathExists=/var/run/qubes-service/tinyproxy is not met. mkdiring the directory in sys-whonix renders the service startable.
Where would I configure this to permanent? mkdir in that location in the template does not survive a reboot.
I have yet to retrieve a file using curl or wget, but maybe I can ge there with further help from you?
Thanks again.