krux VS specter-desktop

Seedsigner is not the only option in this regards. Look into Krux. It does many things exactly like Seedsigner. And some more still better.

Seedsigner and Krux can do that. They're stateless and air-gapped. With krux you can store your seed heavily encrypted on a microSD, if you like.

Coldcard is a solid, bitcoin only commercial option. If you don't mind a little DIY then Krux or seedsigner might be a good choice too. You can also make your own with an old laptop. Remove the WiFi functionality (rip out the board or antenna) and upload Linux. Install a wallet on there like electrum or sparrow (transfer it over via usb) and you have an airgapped wallet.

This is an interesting one I've been keeping an eye on., it uses a small developer platform as an alternative to a raspberry pi seed signer.

Krux Wallet, software that turns your M5StickV into an airgapped hardware wallet.

https://github.com/cryptoadvance/specter-desktop https://github.com/sparrowwallet/sparrow

You can for example use it to run specter-desktop (https://github.com/cryptoadvance/specter-desktop) on top for example, to use your hardware wallet with improved privacy or even mix them together to create multi-sig setups.

Also, the functioning of your hardware wallet isn't dependent on this corporations still existing. There is various free and open source software that lets you manage your hardware wallet, and even combine them to make multi-sig wallets (https://github.com/cryptoadvance/specter-desktop) . This lets you access all information via your own Bitcoin node, no third party system required, fully decentralized.

Take a look at Specter Desktop (https://github.com/cryptoadvance/specter-desktop) , which is a web interface for Bitcoin Core that lets you use basically every hardware wallet directly with your node.

Specter Desktop v1.14.1 (Released: 08th December 2022) - https://github.com/cryptoadvance/specter-desktop/releases

Alternatively you can purchase multiple devices from different manufacturers and create a multisig wallet that requires multiple signatures from multiple devices. Wallet software like Specter-Desktop can help you with this. They also have a DIY signer https://github.com/cryptoadvance/specter-diy

What you can do is to use one or more of this hardware wallets with your own node and a software like specter-desktop (https://github.com/cryptoadvance/specter-desktop) on top. This way you are completely self sufficient.

It is most likely an issue that is solved in the upcoming version of Specter; you might be interested in trying this prerelease, or wait for the official release: https://github.com/cryptoadvance/specter-desktop/releases/tag/v1.13.1-pre1

Specter runs in Electrum, but you can technically set it up to be run through a web browser, as long as you're hosting the service yourself.

Specter Desktop v1.9.4 - Release page - Upgrade guide UIUX: Overhaul of UTXO list, handling of locked UTXOs and scrollbar added to tx-table web component; + various bug fixes, chores and docs. See release page for full notes.