https://www.troyhunt.com/heres-why-your-static-website-needs...
If your problem is some ancient device that cannot speak reasonably recent protocols, the solution is to not allow that device on the main internet directly. That might mean the device itself has to live behind a proxy, or it has to use a remote browser, or it might (as you might guess) simply be a matter of decommissioning the device or only using it on a local network.
Any time the general security of a system is downgraded for some edge case, that same downgrade can be used to attack everyone else.