IO7 and IO8 on PICO devkit M-2

[atx823]

Got a ESP32-PICO-DevKitM-2 board and found the pinouts are different from the ESP32-PICO-KIT V4.1 I was using before. IO23 and IO18 are gone, but IO7 and IO8 are new. The datasheet has:

IO7: GPIO7, HS1_DATA0, U2RTS, SD_DATA0
IO8: GPIO8, HS1_DATA1, U2CTS, SD_DATA1

In the PICO-D4 GPIO7 and GPIO8 were not available as those pins were used for the embedded flash. Is it correct that this restriction no longer exists?

What are HS1_DATA0, 1? Nowhere in the datasheet or the tech reference are these functions defined.

Same thing for SD_DATA* and U2*TS. Again, not defined anywhere.

[ESP_Sprite]

SD-card interface (SDIO slave iirc) data lanes, and UART2 RTS and CTS pins