It is the same issue. We have made progress on this in our documentation, which now specifies that it accepts multiple options but always outputs a Store.
But we do not yet have a way of representing it in TypeScript. Unfortunately doing so requires TypeScript 4.3, which is still pretty "new" (https://devblogs.microsoft.com/typescript/announcing-typescript-4-3/#separate-write-types).
Ticket to track (repurposed from the thread linked to above): https://github.com/bryntum/support/issues/3360