Yes, if u-boot on the eMMC boot partition is botched, the USB recovery via UUU is the only option, see @digitalrayne’s solution. The i.MX8MPlus module cannot load u-boot from SD card at all. U-boot on eMMC will prefer boot files on SD card, but for that, u-boot on eMMC has to work.
Addendum: soldering wires is not necessary, one could use a 2-pin JST-PH cable to bridge the usb pins (mostly anything that has 2mm pitch between pins).
Something like this should work: JST-PH 2-pin Jumper Cable - 100mm long : ID 4714 : Adafruit Industries, Unique & fun DIY electronics and kits