7i77 and Pneumatic solenoids

No problem!

Flyback diodes/RC snubbers/transient suppressors/whatever placed close to the driven coil are mandatory with inductive loads in my book, >60mA or not. The inductive kick can be fairly high dV/dt, make a parasitic LC circuit resonate and couple noise into cables that are run in parallel. Chances that it causes trouble is fairly low. But so is the cost of a diode, and the cost in amount of hair pulled out when chasing electrical gremlins that happen only now and then is high.