Hi there,
Yes, the schematic is not good for production…LOL
Why so complicated. The battery you choose is Small the Xiao could charge and manage it no Issue’.
You have the plus and minus connected together on the IR and UNLESS it’s some type of Parasitic power scheme 
I never seen b4 I would fix that!
you would be better off using the battery pads an RGB LED and a switch. KISS
principle applied.
HTH
GL 
PJ 
