I'm behind a closed NAT and my ISP won't cooperate.

Is renting a VPS for SSH tunnels a good idea? Looking for a solution for tunneling out of the NAT with support for non-https ports.

A Cloudflare tunnel would bypass NAT. I don't know enough to recommend for or against it.

Yes, I would recommend to setup a wireguard tunnel between your vps and homeserver.

Then you can just expose whatever port your want on the VPS and forward the traffic to your server.
I use nginx to forward the traffic to my server, but there is different reverse-proxy you could use.
Bonus is that your don't expose your home IP

Tailscale also may be an option.

I'm behind CGNAT with my ISP. I have a VPS which I use to tunnel traffic back to my home network with Wireguard. That gets terminated on the outside of my router and specific ports get forward in from there. Works well enough.

If it's just for your own usage tailscale is probably the easiest solution. It create a tunnel between you and your server.

If you want to share your services with friends and family and not everyone want to use tailscale then I'm using pangolin on a VPS and I'm quite happy with it.

I do have a static public IP from my ISP but I prefer to not have DNS records pointing directly home, I'm more comfortable with it passing through a public VPS

Pangolin can do exactly all of this, but it does require a vps

How well does it run on a shared CPU VPS with the recommended specs?

Works fine for me. Havent had any issues at all. I'm only running a few services for me and my gf.

There is one public facing service hosted on the same vps as the pangolin stack and that gets a fair bit of traffic, but everything runs fine