Probably the mechanical designer thought it would be sturdy. 2mm is just not enough for pressing.
A longer pressed part is worth more, with a longer pressing. By the way, the aluminum heatsink here is a very soft material.
Electrically, I can imagine that the FETs can't transfer the heat, which is why there will be a distorted radio frequency output over time.
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Gyula HA3HZ
HA3HZ