I have no real conclusion here, but sort of land on the side of "Why wouldn't you expand it?"
The abbreviation of e.g. isn't a good example. It is hundreds of years old and taught in schools. It is essentially a feature of the language (or at least of writing the language) and can hardly be compared to the far more recent initialism NVR. It is ubiquitous and all native English speakers should know it and all non-native English speakers should learn it.
VCR is an example that is almost always referred to solely as its initialism. However, this became a completely ubiquitous term. Early advertisements didn't say "VCR", they said things like "video recorder"[0]. Once it was ubiquitous non-specialists knew what a VCR was even if they didn't understand the initialism and they were marketed just as "VCR". One could make the case that "VCR" stopped being a pure initialism and become more of a word. (VHS on the other hand... not expanded in that video.)
Is NVR ubiquitous enough? BestBuy sells them without expanding the initialism (in the examples I checked), so maybe. However, I bet if you sampled people, the majority wouldn't be able to tell you. And BestBuy selling them this way may have more to do with limited 'item title' space.
It might be the case that it is well-enough known among people who 'need to know' like security folks. I'd argue that's probably not meaningful if BestBuy is retailing them to the public.
Maybe a better example is something like an air-admittance valve (AAV). Most people have never heard of it, but all plumbers have heard of it. In context, anyone can probably figure out what it does. And yet Oatey "correctly" (according to style rules) identifies the name and puts the initialism in parentheses[1].
So on the one hand, it may be ubiquitous enough that it doesn't matter (and is becoming more of a word). On the other hand, there's evidence here that it does matter because it isn't ubiquitous enough for people to be comfortable not knowing what the acronym means.
What I can't see is the downside of writing "network video recorder (NVR)" on the first instance of is use at least on the landing page. Everyone has to learn what it means somewhere and it seems like a missed marketing opportunity for it to not be through your product's landing page. It may also reduce friction or aid in SEO. (YMMV, but I get quite different results searching for "network video recorder" and "NVR".)
You're defending expanding these terms (which I agree to some point), but then writing 'e.g.', 'YMMV' and 'SEO' which you could have expanded or replaced by more obvious constructions like 'for example', 'your mileage may vary' and 'search engine optimization'.
The abbreviation of e.g. isn't a good example. It is hundreds of years old and taught in schools. It is essentially a feature of the language (or at least of writing the language) and can hardly be compared to the far more recent initialism NVR. It is ubiquitous and all native English speakers should know it and all non-native English speakers should learn it.
VCR is an example that is almost always referred to solely as its initialism. However, this became a completely ubiquitous term. Early advertisements didn't say "VCR", they said things like "video recorder"[0]. Once it was ubiquitous non-specialists knew what a VCR was even if they didn't understand the initialism and they were marketed just as "VCR". One could make the case that "VCR" stopped being a pure initialism and become more of a word. (VHS on the other hand... not expanded in that video.)
Is NVR ubiquitous enough? BestBuy sells them without expanding the initialism (in the examples I checked), so maybe. However, I bet if you sampled people, the majority wouldn't be able to tell you. And BestBuy selling them this way may have more to do with limited 'item title' space.
It might be the case that it is well-enough known among people who 'need to know' like security folks. I'd argue that's probably not meaningful if BestBuy is retailing them to the public.
Maybe a better example is something like an air-admittance valve (AAV). Most people have never heard of it, but all plumbers have heard of it. In context, anyone can probably figure out what it does. And yet Oatey "correctly" (according to style rules) identifies the name and puts the initialism in parentheses[1].
So on the one hand, it may be ubiquitous enough that it doesn't matter (and is becoming more of a word). On the other hand, there's evidence here that it does matter because it isn't ubiquitous enough for people to be comfortable not knowing what the acronym means.
What I can't see is the downside of writing "network video recorder (NVR)" on the first instance of is use at least on the landing page. Everyone has to learn what it means somewhere and it seems like a missed marketing opportunity for it to not be through your product's landing page. It may also reduce friction or aid in SEO. (YMMV, but I get quite different results searching for "network video recorder" and "NVR".)
[0] - https://www.youtube.com/watch?v=vQ9nkyo01HQ [1] - https://www.oatey.com/products/air-admittance-valves-aav