You’d create a “new” wallet in Sparrow, but when setting the wallet up, you hit the camera icon next to the descriptor in the wallet settings.
Discussion
I was able to get it to work using "New Wallet"!
Friendly feature request to #[3]:
Allow users to accomplish the same thing through the "Import Wallet" dialog by adding a Scan button next to the Load File button on the Output Descriptor row.
This will make writing directions for disaster recovery or inheritance *much* simpler.
Thanks!
-Sparrow Respector