I think proxy pallet deserves revisiting its feature set and scope, whether the solution is adding extra features or writing new pallets it’s up for discussion.
One of the things that I would be more interested in tackling is to “fix anonymous proxies”. I’m developing Fido, an extensible noob friendly multi-wallet ecosystem that wants to abstract on-chain accounts as much as possible, anonymous proxies are a great(but a bit lacking) tool that I’d like to make the default for user’s accounts, for example we integrate with matrix so users can login just with a matrixID and their homeserver’s favorite credentials(e.g. WebAuthN), thanks to matrix each device already manages its own set of keys from which we can derive substrate accounts, there’s also a decent solution for secure backup of keys, cross device signing for verifying new devices, etc.
End goal is to make people forget about private seeds and have confidence that losing their phone doesn’t mean losing their life’s savings. Users will have many devices that can include hardware, web, mobile, desktop, hosted and more kind of wallets, that should just be proxies to a key-less on-chain account a.k.a. virtual account that can be managed in probably more ways than it is currently possible, e.g. depending on the kind of wallet users set much more granular restrictions to what calls are allowed, what amounts, max weight?, perhaps dynamic time delays, definitely paying fees from the target account(taking multi-asset scenarios into account) that could relate to fee-less transactions that enable things like authorizing a third-party to e.g. submit a vote on my behalf so I don’t need to pay for it.
To enable all this we might need to break up proxy pallet, virtual accounts might better live in the system pallet for example as noted by @xlc.
Curious to hear more ideas and use cases related to this pre-authorization topic 