adry26 looks like the team is focused on improving browser functionalities rather than extensions support (except for 1Password which has been addressed in the latest release)
I use a lot BitWarden and MetaMask but unfortunately none of them is currently working as expected: BitWarden just works partially (issues with Autofill and SimpleMail API integration) while MetaMask does not work at all.
I've already pointed out all these issues to the devs, though. 
20
MetaMask extension doesn't load
- Edited
Metamask should work when installed form popular extensions. If that is not the case please post exact steps to reproduce.
looks like the team is focused on improving browser functionalities rather than extensions support (except for 1Password which has been addressed in the latest release)
Not sure where you got that? From the release notes of just the last version:
1Password extension does not autofill #28 @Vlad
Vimium - ⇧F opens link hint in same page #225 @Fortrikka
Dashlane 2FA codes does not work #5461 @GrasPlukker
Dashlane autofill does not work #5460 @GrasPlukker
Can't install Keeper from Popular Extensions option. #5481 @TCat
YouTube age restriction bypass userscript not working #5559 @minte
Atrocious performance with Dashlane Chrome extension #5111 @ntoxeg
Fixed 1Password & Notion extension shortcuts 'CMD+Shift+X' and 'CMD+Shift+K'
Installing Bypass Paywall has not been fixed #5501 @Honcharenko
Slowly consuming more memory when using Revolut Shopper extension #5535 @prpl
Malwarebytes Browser Guard Extension Does Not Work with Orion RC But does work with Orion Beta #5576 @markbyrn
Calculate correct Chrome extension ID from key provided in manifest (if applicable)
Enabled web-ext schemes for cross-origin requests
Added browser.storage.session API
Added support for injection.word in chrome.scripting.executeScript
Implemented support for getting available update information for extension installed from chrome/firefox store (browser.runtime.requestUpdateCheck)
Improved performance of runtime.sendMessage
Fixed context menu for toolbar item in manifest V3
Fixed browser.idle API events
Fixed callback for browser.scripting.insertCSS
Fixed browser.tabs.query (when tab url contains reference fragments)
Fixed browser.tabs.onRemoved
heisznberg Same situation here. After new update, MTM extension keep loading popup, not work like the old version.
Vlad sorry about that, my intention wasn't to underestimate your work and effort by any mean.
I greatly appreciate all the work behind Orion and I've loved this browser since switching to it, would never go back to chromium-based browsers. I pay big respect to you and your development team, Vlad.
With that being said, yeah you definitely proved me wrong
Would love to see BitWarden and MetaMask being fully functional in the next RC
5 days later
Metamask and Bitwarden are the two most important extensions to me, so if either of them is not working in Orion, there is not really a reason for me to make the switch. As much as I love the browser so far, I will have to postpone the switch 
a month later
Fixed in RC, out today.
21 days later
a month later
Latest RC:
beware that Metamask only works if installed from popular extensions, it won't work if you get it from firefox add-ons (stuck on loading loop). Screen record here
6 months later
Update on this, as of today: Metamask extension still fails to load (installed from Popular Extensions) and gets stuck.
Leaving a screen record here
Details:
Orion Version 0.99.127.2-beta (WebKit 619.1.1)
MacBook Air (macOS Sonoma Version 14.0 build 23A344)
Yes, MetaMask on Orion is not really fun to use on Orion. If it works, it is painfully slow, and sometimes websites do not accept the signing or forget it immediately.
I would love to see more support for it. After all, it seems to be one of the main reasons, at least in my situation, to use Orion over Safari.
20 days later
As shown in this screen recording, Metamask extension is not detected as installed within sites that require connecting your wallet.
This makes the extension basically unusable since you can't interact with applications.
To recreate head to https://www.codehawks.com/ and click Connect Wallet on top right of the screen. You should notice that it does not get detected, and consequently you can't connect to the application
The expected behavior is to connect succesfully and that the Metamask extension completes all interactions smoothly
0.99.127.3.1-rc (WebKit 619.1.11.111.2)
Sonoma (14)
a month later
Merged 1 post from Metamask extension can't be detected.