[j-nsp] Cut through and buffer questions

[james list]

Hi all
Questions:
1) is MX family switching by default in cut through or store and forward
mode? I was not able to find a clear information

2) is in general (on MX or QFX) jeopardizing the traffic the action to
enable cut through or change buffer allocation?

I have some output discard on an interface (class best effort) and some UDP
packets are lost hence I am tuning to find a solution.

Thanks in advance for any hint

Cheers
James