Hi PJ, The expansion board looks good, when I was designing the XIAO ESP32S3 before, I didn’t plan more add-ons at the time except for the camera expansion board, and combined with cost considerations, I didn’t pre-solder connectors on the XIAO ESP32S3.
Overall, it’s great to see a perfect fit like yours come along, I’ll keep watching for a while and if the call for connectors is high or more interesting expansion boards come along, I’d be more than willing to push together for Seeed to release a version of the XIAO ESP32S3 with connectors.