Clark You should check out FUTO keyboard. It does not have this feature yet, but they have several dedicated paid programmers that actively close open issues in their Github. There is a huge amount of added features that is pending for the next release. Allready the keyboard is very stable. It's a very promising new keyboard on the block. It's free, but they want people to pay for it, to support development.
The FUTO organization are working on several open source and high quality privacy friendly apps and services.
https://github.com/futo-org/android-keyboard