MG T-ABC

In the latest issue of totally t type 2 an article discusses closing the hole on the top of the rocker arm, do we agree this is a good idea? Isn't it there to lubricate the valve and rocker arm contact area?

for those who think metric; the holes are 2,5 mm just the right size to tap 3 mm thread.
would a compomise make sense- every second hole in the rocker blocked??