Hi! Some bugs were brought to my attention, so I went ahead and added the currently coded (and some sprites) for content that was planned for v0.6.
I've also updated the sprite status spreadsheet with preliminary placeholders for sprites for upcoming forms, but I've spent a bit too long on the computer today and won't be able to continue updating the spreadsheet or the Alt Dex post until later in the week.
In the meantime, here's the notes:
v0.5.9 New Forms
Flame Slowpoke, Flame Slowbro, Mega Flame Slowbro, Flame Slowking
Storm Dragonite
Toxic Dunspa