After carefully soldering this hack I plugged it back in and ... nothing happens. Everything works the same as before.
EDIT: I've found this SD-card module on google: https://grobotronics.com/waveshare-micro-sd-storage-board.html . Would this work in combination with the USB Host Shield?
ESP32 has more than 1 SPI controller so you might connect SD reader and USB host to different controllers.https://github.com/espressif/arduino-esp32/issues/1219