Some vs a lot can they be interchangeable?

[CED] lists the 'quite a lot of' (as opposed to 'more than zero') sense of the polysemic determiner some:

some determiner (LARGE AMOUNT)

a large amount or number of something:

• It'll be some time before we meet again.
• It was some years later when they next met.
• We discussed the problem at some length.
• It took some effort to get the thing upstairs.
• In the end she agreed but she took some persuading.
• Will you phone me back - it's a matter of some importance.
• Green's new world record will take some beating.

In each of these cases, 'some' may be substituted by 'quite some' and/or 'quite a lot of' and/or 'quite a few'. Note that this sense of 'some' may be used with both count and non-count nouns.

Note also the grading into the corresponding [determiner+adjective] usage:

• That was some party! (= 'That was a remarkable party'; see Merriam-Webster) This usage can be seen neither as purely quantitive ('a bit of / a lot of / a small / a large') nor purely adjectival (*'That was remarkable party').

The specific string [determiner [some] + noun/ing-form [N]] are not what force the 'large/largish amount' sense, at least not always:

• I have some time now; let's go for a walk.
• Some years are wetter than others.

However, the 'more than zero' and the 'certain examples' senses are not readily available with say 'persuading', 'importance' ... (one sees these are abstract ideas, but then so is 'time'). Of course, one can contrive exceptions ('Some effort will always be required' / 'These clothes lines are all too short. We'll find some length that will fit.')

• 'There is some juice in the glass' would almost always default to the 'more than zero' sense. The 'large amount' sense would be overblown unless one were with say Hagrid.

• 'There is some water in that reservoir' is, however, ambiguous without context; heavily stressing 'some' (perhaps bolding rather than using italics in print ... and probably an exclamation mark at the end of the sentence) forces the 'an appreciable amount' sense. A reservoir can hold a considerable (heading towards 'vast' here) amount, so this is not an incongruous usage. But the 'It's not empty' sense is also readily available.

Yes, there's ambiguity here. As usual, context will disambiguate in practice.