A: No. The manual explicitly states the board is hardwired for UART. Attempting SPI will damage the driver.
This board is powered by an ATmega328P and typically runs GRBL. Main Documentation/Readme: MKS-DLC GitHub Home Hardware Pinout: MKS DLC V2.1_001 PIN.pdf Schematics: MKS DLC V2.1_001 SCH.pdf MKS DLC32 v2.1 (32-bit / ESP32-based) makerbase mks dlc v21 manual link
: Instructions for flashing GRBL firmware and configuring the board for your specific machine. Key Technical Specifications Processor: High-speed 32-bit ESP32-WROOM-32U module. Input Power: Supports DC 12V–24V. makerbase mks dlc v21 manual link
If you need the that originally came with the board, it is not available for separate purchase from Makerbase, but the PDF above matches that manual exactly. You can print it for a physical reference. makerbase mks dlc v21 manual link