I don’t know that there is necessarily harm in doing this, but I don’t see that there is any advantage either.
When you say intermittent suction are you referring to periodically discontinuing the suction, this might be an attempt to transition to water seal. If you are referring to placing the suction control on intermittent mode I have personally never seen this done. Someone might do this prior to transitioning to water seal, however as short as the intermittent periods of suction/no suction are, I doubt that this would be effective.
Has one of the providers at your facility actually done this? If so, have you considered asking her or him what the rationale is?