I have a Dell Latitude e7250 which doesn't officially support NVME via UEFI and thus has no bootstrapping for it. I installed a Toshiba RC100 2242 NVME drive in an M.2 slot designated for WWAN cards and it does indeed function as a drive just fine. So I need to install my bootloader to a device that can be recognised by the UEFI. I can either use a small USB key or an MSATA drive.
I've had no luck with the installer in trying to designate another device for the bootloader when using full disk encryption. I have managed to use the manual partitioner for an unencrypted install with the bootloader on a flash drive but this isn't desirable. Specifically I'm trying to use Ubuntu MATE 18.04 or 19.04.
I'm wondering if there's a technical limitation that I'm missing. If strictly necessary I'll just fall back to an encrypted home partition.
Thanks in advance.