Don't do passkeys

Webauthn is nice as you can use your existing hardware device (trezor / bitbox etc)

we use cal.com

google is a hard no

Ideally yes, and if you are connecting direct to each signer then it will probably be smooth

Problems are more likely when you ask any remote signer counterparties to provide their xpub, as signers won't necessarily provide m/84' by default

But yeah, it's fine to use the same seed for everything, and for max privacy you might want to consider using unique (hardened) derivation path / xpub combos for each multisig you join

If you export your single sig xpub and whack that in a multisig, it will have the wrong derivation path, meaning you won't be able to sign psbts (the workaround is to change the config file to show the correct derivation path)

Also, your single sig xpub with single sig derivation path may leak your single sig balance / transactions

YMMV depending on the wallet you use, and whether you use a hardware or software signer

The point is, that each derivation path results in a new xpub, and some multisig wallets / signers are more forgiving than others in dealing with this

You should be aware that many wallets do not make it easy to change the derivation path, or to use non-standard derivation paths, after you set it up

Be sure to test!

same

Sometimes stores in such jurisdictions will sell you a sim based on just a photograph of an arbitrary id card

Otherwise, it's a good idea to ask / pay someone else to buy it, indeed

Using a sim which is kyc'd to your slave name must really be avoided

Put a sim card in an old phone and hotspot when you need it

This way multiple people can share one GSM locator, and you have the possibility to swap it for a new device (identifier) without the hassle of transferring data across

Phones are smaller and tend to have better battery than travel routers, you can share the charger, and - they double as an actual phone in case of emergency

Airplane mode is one of the primary defences against location tracking

We'd love to see this enabled by default (first boot) in @nprofile1q...

https://glok.me/guide-the-strategic-use-of-airplane-mode/

The best solution is to avoid sim cards entirely and use your phone with wifi only

Well said