The Expansion Board Base for XIAO with Grove OLED is a great product for prototyping, especially with the added RTC battery and SD card slot.
What would make this even better would be having the OLED on standoffs so it would be higher on the board. This would make it work much better in enclosures and avoid the recessed look.
A second option would be the Expansion board with a removable OLED, but retain all the other features (RTC, SD, ect.).
My challenges in building prototypes is almost always the location of the display in an enclosure.