Powering XIAO SAMD21 with 3V3 pin

Hello !
I bought some XIAO SAMD21.
They will be integrated in a music synthesizer and powered “on demand” during the the tuning procedure.
Once the procedure is finished, the XIAO is powered down.
It seems that XIAO 3V3 power pin is wired directly to it’s LDO’s output.
I can’t find any info about this powering method, and if it would be better to power it with 5V, thru the integrated LDO ?
I had a look to the LDO’s datasheet, there’s no info about wiring a 3V3 supply to it’s output.
So here’s my question : is it better to power the XIAO with it’s 3V3 pin or it’s 5V pin ?
Thank you for your help ! :slight_smile: