2017 F-150 on 3.0.20204 but Cyanlabs says MY20+

Of course it it’s, I’m not sure why you have doubts exactly.
The APIM the vehicle has is flagged MY20. You may be confused about the APIM being a J series one, but Ford started some time ago to release J series replacement APIM with MY20 hardware to the market (Ford’s logic).

Do not reformat it unless you want to brick it.
Have you searched the forums for the APIM model?, you won’t find happy endings.
If you still have doubts, you can always unmount the unit and check the stickers.

This is your best shot → Tutorial: Sync 3.0.20204 with 2020 NA2.20 Map Installation