Not sure if it fits your requirements exactly but I just put a service behind TwinGate and it works well for my usage case. I can allow my wife secure access to services she needs to access from anywhere securely - she just opens the app to connect and she can access what she needs.
I haven’t but you can enable 2FA, as well as restricting based on things like hardware, OS and whether a device has biometrics.
I had to install a firmware update in my Nike trainers not long after I got them. Welcome to the future.