Help with ESP32-S3 pins

Hi, I am just making the transistion from the old ESP32 to the ESP32-S3 for a new PCB design (custom board for my son’s toy robot). Things seem to have gotten a bit more complicated and I would hate to unnecessarily wait for a new round of PCBs only because I screwed up models or pins, so I would be very thankful if someone could check/confirm a few things:

I ordered S3-WROOM-1-N8R8 modules. So as far as I understand 8MB of Flash and 8MB of PSRAM.

  1. GPIO47&48: This has nothing to do with the ESP32-S3R8V, and I can normally use GPIO47&48 at 3.3V, right? Due to their physical location, I planned them for I2C.
  2. GPIO3: I have connected GPIOs 39-42 to an ARM JTAG header. GPIO3 is pulled-down and connects to the base of a BJT to control a buzzer. This should be fine compatible the appropriate FUSEs set?
  3. GPIO35-GPIO37: I have connected these to a SPI header for later use. If I read the datasheet correctly, they will not be available with 8MB of PSRAM. Can I still use these pins for SPI with the N8R8, if I don’t use the PSRAM, or only use 2MB like the N8R2? Would I achieve that with
build_flags = 

for platformio with arduino-esp32?