I am in the process of building/ installing MX on a new Dell Inspiron (mine is a 5493). :lipsrsealed:
After I created my boot USB (via MXTools) I attempted to boot the Dell Inspiron using the One Boot Option (F12). The new Dell BIOS Boot process did not recognize my traditionally created MX19 USB. The MXTools Live USB creation (dd only option) created a Boot USB that was (for this Dell) an unrecognizable device. I recreated my boot USB (using the same USB device) with unetbootin (because of its *buntu bias; Dell is also *buntu biased).
Anyway, the unetbootin device is/was recognized and runs fine on the new Dell. I did not need to do anything fancy to the hardware beyond recreate a readable piece of media/device.

I hope this helps anyone in a similar position.