I'm not "refusing to add TLS support" I insist that the certificate is safely isolated in a separate process for security reasons. There are many ways to skin that cat.
the whole point of varnish software keeping a public version of "vinyl cache" as "varnish cache" with TLS is to give people a way to access a FOSS version with native TLS.
I think TLS is table-stakes now, and has been for the last 10 years, at least.
fwiw; Varnish Software still maintains and supports hitch, but we can't say we see a bright future for it. Both the ergonomics and the performance of not being integrated into Varnish are pretty bad. It was the crutch we leaned as it was the best thing we could make available.
I would recommend migrating off within a year or two.
haproxy supports both the offload (client) and onload (backend) use case. This is the main reason for why I personally prefer it. I can not comment on how well hitch works in comparison, because I have not used it for years.