Earthing a dish and earthing a dream are 2 different things IMO.
A dish should be earthed regardless in-case of lighting strike. Its standard practice on cband installs and would be good practice on any metal dish.
I however never earthed a LNB/receiver until i got my DM recently.
Lets also note that most lnb holders are plastic and insulate the dish from the LNB.
Just my (limited) thoughts on the matter.
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