Redjard

i2p doesn't really have exit nodes, it's mostly for i2p internal connections.
The only exit I know is stormycloud.i2p, and that one is somehow immensely limited ro the point of it being hard to load clear-net text pages.

We can't make enough. And crispr is for inside cells, there is another layer needed for getting it there, like a virus shell for example.

Careful, Google is currently forcing apps to migrate from SafetyNet to PlayProtect!
SafetyNet is used by tons of security theater apps like banking 2FA. It is an API of play services.
PlayProtect is basically the same but you have to talk to it though google play. This is a blatant move by google to make exactly what OP is suggesting impossible, and means that if you do this, you may soon see many apps break that you are forced to use.

Yes, those could be detected.
Ill see how large that portion is on my system in a bit, but I would expect it to come out as the minority.

Non-detectible ones I can think of rn:

• Tab muting manager
• VPN manager
• link redirect skippers
• stats printers, like a tab counter
• dynamic shortcuts, like opening the archived version of the current page on archive.org
• old reddit redirect
• cookie managers

Many more of the ones you listed won't be detectable on most websites.

userscript managers (grease/tamper/violentmonkey etc.)

A userscript manager is by definition detectible only on pages you define or install a userscript for. Even then, modern userscript managers like tampermonkey are running scripts in a separate scope that is completely sandboxed from the actual websites js context, you can't even pass an object or function to the website and access it there, it will fail.
Youtube has actively fought some userscripts and failed, which they probably wouldn't have if those userscripts were detectible.

User theme managers should be similar, but I can't comment on them as I don't use any.

page translators

Translators are only detectible when enabled.

addons serving in-browser ads

Why would you have an addon that serves ads?

site-specific UI improvements (RES, SponsorBlock, youtube/SNS tweaks)

Are site-specific, i.e. not detectible anywhere else

privacy blockers (CanvasBlocker/JShelter/etc.)

Please don't use those anymore, use only uBo. Same for uMatrix.
uBo is pretty good about not being detected, for obvious reasons.

I found this is the only thing I found on a quick search.
It would indicate that chrome does disclose addons (so maybe don't use it for yet another reason).
For Firefox you can only look for changes typically performed by an addon, something like adblock should be detectible but networking layer stuff like an I2P tunnel should definitely not be.

Most firefox addons dont even have the permissions needed to change anything a website could observe.

I don't see any extension info and I don't see how there could be any. There isn't any api for gaining this info in ff at the very least.

There are other issues, but most extensions can in fact not be detected by websites, unless they specifically add something that makes them detectable.

TPM isn't all that reliable. You will have people upgrading their pc, or windows update updating their bios, or any number of other reasons reset their tpm keys, and currently nothing will happen. In effect people would see Signal completely break and loose all their data, often seemingly for no reason.

Talking to windows or through it to the TPM also seems sketchy.

In the current state of Windows, the sensible choice is to leave hardware-based encryption to the OS in the form of disk encryption, unfortunate as it is. The great number of people who loose data or have to recover their backup disk encryption key from their Microsoft account tells how easily that system is disturbed (And that Microsoft has the decryption keys for your encrypted date).

The default on android is to give every wifi network its own random but static mac.

PHP has ben JITed for a while now too.
I don't recall it being known as slow compared to python even before that.

background: #f0f

This really seemed like a good simplification until you threw in that d'Alembert operator at the end

Default linux works too ofc, I didn't know they took that route.
Most other browsers have very specific useragents, so the main pool of same useragents will be hardened browsers anyway.

Thank you for checking

edit:
https://github.com/TheTorProject/tor-messenger-build/blob/581ba7d2f5f9c22d9c9182a45c12bcf8c1f57e6e/projects/instantbird/0001-Set-Tor-Messenger-preferences.patch#L354 would indicate it should be Windows, Ill check later.
Try it with high security settings in tor, it might be something like canvas. Did you enable any permissions for the website?