TLS vs self signed certificates problem

[drawkula]

Once upon a time I posted into the mailing list:

I can strip down the HTTPS example in the manual to the bare minimum,
turn it into accessing HTTP, NEX, NNTP and other protocols, add back TLS
to e.g. access NNTPS, but with the average Gemini server I'm biting on
granite.

Not really understanding the error OpenSSL shows, I just assume that it
fails with servers using self signed certificates and succeeds with some
others because they (re)use a (sub)domain they already have registered
with some authority for their HTTPS server.

Similarily they seem to succeed or fail using Ncat to access them
depending on using "-ssl" or "-ssl-verify" to connect.

Is there a way to teach Gambit an additional option for make-tls-context
to do similar?

While trying to produce more examples an answer showed up (body (without quoted parts) only):

The way I use to get around it was to
sed -i -e 's#SSL_VERIFY_PEER#SSL_VERIFY_NONE#g lib/os_io.c

So the remaining parts of the question now boil down to: Can this change be turned into an option of make-tls-context or be switchable at runtime by other means?