Hi,
Thanks for sharing this board, I looking to make my own also, and just wanted to be sure, your on board LED is connected to D7 and as you state to select pinout 32 pin standard from MegaCoreX, I think with bootloader your LED is not blinking because bootloader assume is on A7 which is PD7 and notD7 (PA7). Is that correct (except if you build your own bootloader with D7 of course)?