HTTP(S) source on a custom port

How can I customize the port HTTP (or raw HTTP) source listens on in Cribl.Cloud?

10080 is the default, and https://docs.cribl.io/stream/ports/#cloud-ports seems to indicate that I can only use 20000-20010 for additional sources?

I am trying to get a webhook configuration working for DocuSign and it looks like Docusign only supports 443, 1443, 2443, etc (https://support.docusign.com/s/document-item?language=en_US&bundleId=vob1727899215236&topicId=zjq1665170940873.html&_LANG=enus).

Seems like this won't be the only challenge I’ll need to overcome based on the authentication methods DocuSign and Cribl support, but it's the first obstacle i see.
I tried enabling an HTTP source to listen on 1443, but when testing with https://www.geocerts.com/ssl-checker it's telling me that this port isn't responding (while 10080 is), so it appears something on Cribl side….