Why use A5 and makes unusable I2C?

Arduino(TM) Shields KA03/VMA03
2

Hi

Pin A5 was chosen with no particulary reason (probaly the first pin)

But you can cut the trace between pin A5 and C3/R9/R10

And then wire C3/R9/R10 to another pin.

Best Regards,
VEL337