If I want to connect Seeed Studio XIAO ESP32S3 Sense to this extension screen, will there be a conflict with two TF card slots?

A: This does not create a conflict. The different SD card slots are controlled via chip select, if you want to use the microSD card slot on Sense, the chip select pin should be 21, if you want to use the microSD card slot on Round Display, the chip select pin should be D2.

We have examples of using both hardware and microSD cards in the S3 Sense camera tutorial.