I was using 1Password to manage things like passport details, credit/debit card details, driving licence details, etcetera – including images of each of the above. I recently migrated to Proton and it's incredibly frustrating that I can't do the same.

+1, this is critical for me to really use "notes" in proton pass

CRITICAL!

Proton Pass' inability to support file attachments is why I just renewed my Keeper Password Manager subscription -- I would love to eliminate that expense, since I pay (a not-insignificant amount) for a Proton Unlimited account.

I have plenty of room in Proton Drive. It seems like integration between the two would be a sensible approach.

[Example Use Cases:
I have an uploaded photo of my health insurance card stored with my health insurance provider account login credentials.
I have a PDF of my proof of auto insurance stored with my login credentials for my auto insurance provider.]

Definitely agree. I'd like to attach small text files for keys/backup codes etc. I understand I can paste in a text field but it doesn't copy to clipboard when you select it.

it could also be an integration with Drive.
Link files from Drive would be very nice.

In secure notes that we set in Proton pass should be useful add some small files (as text files) or some images, as QR codes for 2FA authentication or other information. Thanks

I'd like the option to store a photo, i.e. from my ID card or driver license.

mentioned this in the ProtonPass SubReddit as well - it is the ONE feature that's preventing me from making a full migration from Bitwarden. Suggest matching Bitwarden's file size limit if possible, at least all 10MB to capture screen clips and other small items.

Enpass user here.
I frequently attach photos/screenshots of backup codes, ID cards, prescriptions, etc.

Yes, Enpass allows you to create separate fields with one being for photo attachments. I use it to store photos of ID, insurance cards, etc. I also use to store screenshots of backup codes, etc.

In Keepass and LastPass I can add small files to my password entries, typical keystores for HTTPS with client auth. Please add such a feature to ProtonPass.

This would be very useful indeed. As a user of Bitwarden, this is a feature I would really want before making a switch

This is critical. Key files, scans of IDs, etc.

I was very surprised coming from LastPass that attachments are not currently possible.

This is what's preventing me from switching at the moment.
I currently use KeePass and for some item it is critical to be able to attach files dorectly in the password database.
Examples are backup recovery files (e.g. for Synology or borgbackup), recovery codes for 2FA (that can be text, images or pdf; images are best for security).

Attachment ticket with the most votes: https://protonmail.uservoice.com/forums/953584-proton-pass/suggestions/46854553-support-tiny-file-attachments

The app needs to allow photos or a scanned document to be added. Especially in notes. Many other password apps allow this feature.

This sounds like a perfect integration with Proton Drive! Attachments should be able to be added to specific password AND note entries in Proton Pass. Adding an attachment should transparently upload the file to a location on Proton Drive, and allow the attachment to be accessible at a minimum, from the password/note entry in Proton Pass, and optionally by going to the actual stored location within Proton Drive.

Proton is uniquely positioned as one of the few (only?) companies with a password manager and secure cloud storage as their core product offering. Google, Apple, Microsoft don't count here as none of them prioritize their password managers, and certainly don't care to properly integrate them with their cloud storage.

Useful file attachments could also be screenshots or PDF.
Maybe this functionality could be integrated with Proton Drive using a predefined "special" Pass folder.

Sometimes a credential is a small file (<1MB). That could be certificate + private key, an SSH key or a proprietary license file. I don't want to rely on a separate solution to handle such secrets. I expect a password manager to also support that use case.