You don't set delay to subdivisions of milliseconds….You probably mean one delay at 350ms and the other at 525? If so, you could just set them at that. Or you can try to set one at dotted eights (1/8.) and the other at 1/4….or 5/8, I'm no U2 expert (Ahem…Eventide, that is not 5/8…it's 5/16!). Then tap the desired tempo.