Thx for your replies.
We shared the shame idea, but yesterday I found another solution.
Because princexml uses curl, I can use the curl supported environment variables http_proxy
By removing the proxy parameter from the command
And define the proxy rules in the environment variables that curls supports, I was able to exclude specific and wildcard domains from the proxy.
https_proxy=export-proxy:3128 http_proxy=export-proxy:3128 no_proxy=www.wikipedia.org,.lorempixel.com "/usr/bin/prince"
more information can be found here: https://curl.haxx.se/libcurl/c/CURLOPT_NOPROXY.htmlI tested this on Debian 10
Hopefully its is useful for others.