Is the construction "most + singular noun + singular verb-form" acceptable?

I'm studying grammar, and this sentence is worrying me:

Most lightning occurs within the cloud or between the cloud and ground.

I thought that the allowed construction is "most + plural noun + plural verb-form"

for example "Most students like [games]".

But "Most lightning occurs" is of the form "most + singular-form noun + singular verb-form"

Is this also grammatical?

Is it an ellipsis:

Most [of the] lightning occurs ... ?

This is an interesting question. The only problem with the standard count-noun usage

Most phones are now smart.

is deciding what percentage of the referent might be indicated by the quantifier (strictly, over 50%? or pragmatically, over 70% say? ...).

But the use of 'most + non-count noun-usage' is rather involved.

Few would challenge the acceptability of:

Most lightning occurs within the cloud or between the cloud and ground.

Most tap water in Erbothnia is perfectly safe to drink.

Most rice is produced in upland systems.

Most plastic is not recyclable.

Most anger is generally short-lived.

Most beauty is an illusion.

This indicates that though the associated nouns are non-count (in the given usages; plastic and beauty for example have obvious count variants) there is a notion of quantifiability (extensiveness or different episodes) about the referents. Of course, 'most' used with non-count noun usages is equivalent to say 'the greater part of' or 'the greater number of examples of'; the fuzziness of definition is retained.

However, there seems to be a restriction on the nouns used, which is not the case with count nouns. This will be partly because some concepts are hard to quantify, but partly because of unfamiliarity.

In general, most forest is at altitudes between 1,000 and 2,100 metres.

(I'd say doesn't sound totally natural, though I'd say is fully acceptable. 'Montane forest is characterised by relatively strong vertical zonation' sounds fine to my ears; the non-count usage of 'forest' is not itself a problem.)

?Most sophistication is found in the suburbs of large cities.

(But 'And yet, for all her sophistication, there was an air of vulnerability about her' is fine.)

??Most amazement was generated among the 3-4-year-olds.

??Most clarity was found among the Language graduates.

??Most disregard occurs among male students.

?Most dictatorship is not benign.

?Most fire is caused by carelessness.

(The 'very questionable on unidiomatic grounds' calls are mine; I can't find supporting evidence other than low returns on Google searches for say { "most disregard" -"the most disregard", and assessing how many false positives (eg disregard [verb]) there are.) Of course, in most cases the noun usages themselves are not all that common. With the last sentence, the count usage is so common that the non-count usage sounds quite unnatural.