No the beam source we know how to create; it's just that the way to do so requires a factory sized machine that better be feeding 10~30 steppers or a pair for uptime/maintenance windows and then probably more like 50 steppers.

Free electron lasers are not hard at "mere EUV", and the accelerators to feed aren't either, it's just that an efficient setup requires recycling the beam which means bending it back which means a large (factory hall sized) accelerator at the beam energies needed for good EUV light.

Weiss makes the mirrors.