How can there be leniencies with dmai being that there is the issue if terumas maiser?
We do have to take off Terumas Maaser from dmai. The first mishan says that there certain items that are patur from dmai because they usual grow wild. Therefore even regarding terumas maaser they are patur because there is a double safek maybe they grew wild and even if they were home grown, maybe terumas maaser was already separated. See Rambam and Bartenura Dmai 1-1.