Before that is done, I would like to know one thing from you, concerning the firearms from the Dungeon Masters Guide.
The firearms from the DMG are currently available as additional content in the Fan-made Additions Dropbox Folder and GitHub folder. However, I'm toying with the idea of adding them to the sheet as then all WotC material will be available directly in the sheet.
Unfortunately, adding those firearms comes with a bit of a problem. Because they are optional rules, I feel that hey shouldn't be available in the sheet by default. Having them appear in the attack drop-down boxes and their ammo appear in the ammo drop-down boxes serves only to dilute the sheet and makes it even more confusing to newcomers. The alternative is to excluded them by default, just like the Unearthed Arcana material is, but this won't be as clear as you will only be able to see this when you click the "Weapons/Attacks" button in the Source Selection dialogue.
And as always with a difficult decision that doesn't have one correct answer, I'm coming to you!