Do NOT factory reset your jailbroken kindle!
If you hit trouble or get stuck or confused somewhere while jailbreaking or installing things, ask for help instead of abruptly pivoting to the nuclear option. Factory resetting a jailbroken kindle without restoring OTA binaries can get you in a weird state that requires additional recovery to be able to either install the hotfix or official firmware binaries.
Only factory reset if you know EXACTLY what you are doing and what will happen and why you are doing it. If you didn’t understand the last sentence of the first paragraph, do not factory reset unless someone who DOES has instructed you to. This is not some routine troubleshooting step. This should not be a primary go-to in your toolbox. Stop reaching for it every time you hit a bump. Please.