"one of the major reason was use of cartridge in pattern 1853 enfield rifle, the standard issue for the rifle was greased with pork fat and beef fat and as to load the rifle the soldier had to tear of that part
by his mouth which was unclean for both hindu and muslim sepoys. gurkhas compromising of mostly gurung, magar, rai and limbu clan had no problem with either of the fat, beef was widely consumed in eastern nepal."(sirupate_brigade)

wait i get confuse here sirupate_brigade. you said that beef was widely consumed in eastern nepal.
but in one of my visit to dharan, there was no cow slaughterhouse or any beef market. but i saw the
butchers selling live black pigs and pork. In fact i learned that the pork is a central part in
magar, rai & limbu culture. But regarding beef i am not sure. One question arises from here!
Could the food(beef & pork) restrictions by the "high-caste" Hindus had impact on the British officers not willing to recruit them? The good example is the Indian Mutiny.

There was another good example i read in one of the books. That the story goes like this.
The 7th Gurkha rifles along with the Indian units both of the British army were stranded on the desert front against the Germans and the Italians. The British Army were cut off from their main supply and soon their ration(food&water) were running out. The British officer told his men to cut down their horse for food. While the Gurkhas and other British officers and men ate it, the Indian soldiers protested to eat it since they said it was against their religion.
This again comes to the food restriction by some group that the British officers only favor the "martial race"(gurkhas) in their recruitment.
But i am sure Sherpas have also no restrictions on beef & pork. So are there any sherpas in the British-Singapore Gurkha unit?