Print a test strip or a small print, then another nozzle check. Maybe it will get better all by itself. Or maybe it won't but a print will look OK.
A fall-back option is to print in a higher resolution mode that can hide the visible effects of a few bad facets in the heads. That might even lead to an eventual improvement, or maybe not. When I have done back to back Head Checks on shaky heads I have noticed there are often different erroneous patterns.
Have only done a very few "B" cleanings, my recollection is that it usually doesn't use a huge amount of ink. But it can do a variable number of repeats within the cycle which means the amount of ink used is not quite predictable. I definitely agree that if a single B cleaning doesn't do the job the head is probably beyond repair, especially if you get multiple cycles in the cleaning procedure.
If you are less than a year from buying the head, it should be covered by warranty.
For future reference, launch the "Image Prograf Status Monitor" in your program files, select your printer, click the Accounting Tab, Click the Account Button, then under "File" click "Show Ink and Paper Consumed." Note the "Total Ink Consumed" before and after a Cleaning B. I'm not 100% sure if the cleaning will bump that number or not, but it might.