All the QSO’s that I am aware of (including FT8 and EME, as examples) require an exchange of calls, one other piece of data, and _confirmation of reception_ to be valid.  I agree with the suggestion to reduce power, but the stomping on QSO’s in progress is bad operating, plain and simple.  Like a DX pile-up, the onus is on the rover to manage the pile-up and over-anxious callers.

Bill ACITO | W1PA