I have been using the M4 for some time now; the major problem was interference to DAB+ and more importantly GPS reception. This is not uncommon in other supplies, it’s more common in supply’s that can run a PC with the input voltage as low as 6 or 7 volts.
I overcame the noise by designing and fitting the M4 in a special RF enclosure. In some installations there can be a slight glitch on the IGN input (on/off input) with the system in Sleep mode. I overcame that with a simple diode and cap on that line.
The M4 has operated faultlessly after that. With this PSU you need 8G cable minimum for low noise even in low power systems, preferably 4G for systems drawing over 10A (130W).
I have not had a single failure to resume from Sleep or Hibernate for months at a time. No unexpected shutdowns or glitches of any kind.
If you don’t have a problem with interference then it should work fine without any mods.