You have not cleared the SPI. If you were to actually clear SPI from u-boot, the system would not start with NVMe under any circumstances. The launch will work exclusively from the SD card. If you do not use power supplies with PD - you have the opportunity to install the correct u-boot on the SPI and have a normal start from the SD card in any NVMe state (you can have a NVMe system and run any other system from the SD card in any NVMe state).
Do not mislead people, the regular u-boot Radxa has errors and the wrong order of launching from devices. In case of any problem with NVMe, users will have to physically disconnect NVMe, erase it manually on a PC and repeat the entire process of installing the system on NVMe again, the SD card will not work.