I'm aware of no disadvantage in (non-Powerful) head cleanings, at any frequency, so long as you make at least some sort of print that exercises the just-cleaned heads, before doing additional cleanings. Mark Segal may amplify but the risk, as I understand it, is the air-entrainment into the head may follow cleanings unless the cleaning is followed buy some form of printing. This has been stressed especially after Powerfull cleaning. It may be that my facts are not correct, meaning this air-ingestion risk may only accompany use of the Powerful cleaning. Power cleanings are apparently best followed by not only printing but also "resting the printer" for some period before additional cleanings are done. Again I think Mark Segal has given this a lot of thought and written on this topic.
John, the repeated advice I've received from Epson America ProGraphics Support is clean-print-clean-print in cycles till the test pattern is unbroken, for ordinary cleanings. More than once I have been told especially not to implement one power clean after another without printing between them, but the advice applies to all cleaning.