Да, похоже лучше этого не хотеть
If a boot image isn't found with the same architecture, Configuration Manager looks for a boot image that's compatible with the architecture of the client. It looks in the list of task sequences found in step 2. For example, a 64-bit BIOS/MBR client is compatible with 32-bit and 64-bit boot images. A 32-bit BIOS/MBR client is compatible with only 32-bit boot images. UEFI clients are only compatible with matching architecture. A 64-bit UEFI client is compatible with only 64-bit boot images and a 32-bit UEFI client is compatible with only 32-bit boot images.