Any way to affect UA Header / iframe ?
On https://webbrowsertools.com/useragent/, this extension works on the top three methods, but not the bottom three.

Is there any way to make this (or another) extension work on the bottom three?
I'm on Chromium 79.0.3945.88.
I also have FireFox 54.0.1 (64 bit) with an extension called UAControl (caa:addon/uacontrol) that works with UA Header in addition to the top three, but not the two iframe ones.
I have also just found, that the first two "navigator" aggressive tests sometimes fail with this extension (version 0.4.3) and show the real user agent.
Is this just how this is on Chrome / Chromium, or is there any way to make it more reliable?
Just updated to Chromium 85.0.4183.102 (782793) 64 bit and now it's worse. Now, the extension only works on the "normal" test and reports the real user agent on all of the "aggressive" tests.
Would be helpful to know any ways around this.
You can use a local proxy as privoxy: it has instructions on official site to change the user agent.