Impatient aren't we.
If you are lucky the pests did not transfer, but that would be some really good luck.
Before placing in the main tank, in fact before placing in the QT, everything should be dipped in Flatworm Exit and one of the coral dipping products to remove the Flatworm and any other pests. With a report like this about that other hobbyists tank, who knows what other pests there are.
My next advice would be:
We know how to deal with Majano, but
prevention is the best cure. Stay away from Majano at all costs.
Next time, ask about and look for problems before purchase and do not buy from pest infested tanks or until you know how to deal with the pests. Others will hopefully chime in here, but the way I see it,
the QT is for new purchase observation AFTER treatment to remove pests. Sorry but now the QT has become infected. The entire QT needs to be decontaminated by dipping or treated with Flatworm Exit or in the worst case, torn down and start over, Sorry.