Just because a "machine is not used for heavy lifting" does not mean one should cheap out choosing lesser display, lesser speakers, lesser everything. The only possible reason OP should choose the lesser-in-every-regard MBA would be price.
As to RAM, it gets to whether or not one chooses to build a new box to be optimal in 3-5 years, or not. RAM demands have increased every year for 40 years, so folks simply planning on doing what worked in 2022 are making bad decisions IMO. Apple knows, and they suddenly jumped their available laptop RAM by ~6x and doubled base RAM for presumably good reasons.
Obviously one buys what one can afford, but cheapest does not necessarily mean best choice.
I still think the MacBook Air is a better value for the money.
The OP has an iMac Pro that he uses as a main machine, so this would be the support machine.
On day 1, the MacBook Pro is a better machine than the Air. It has a better and brighter screen, and a higher refresh rate. Better sound and camera as well. But it costs $300 more. And is significantly heavier.
The difference in power between the M3 and the M4 may be negligible on day 1 if the OP uses it for basic tasks. This difference is going to get more noticeable as time passes, but then RAM and storage may be the bottleneck before the processor is.
As for the other stuff, it may make a real difference if you are meticulous. If you use it as a secondary machine, perhaps not so much.
I have a laptop with a 120 Hz screen, and I see little to zero difference in real world usage. The difference is much more perceptible in a smartphone than in a laptop.
As for brightness, the 500 nits of the MacBook Air is already good. I cannot see the difference unless I am looking to them side-by-side. It may make some difference if you use the laptop in sunlight, but I never do, and I suppose a lot of people do not either.
The MacBook Pro has a miniLED display, which is of course great. But I do have an OLED laptop, and, while the screen is great, I see no need for it. It makes a lot of difference in a TV, as movies tend to display lots of shadows and dark environments, so pronounced blacks are a must-have. On a laptop, although it is great to have, I would not say it makes so much of a difference.
When I am carrying a laptop around with me, the weigh difference is far more important than a slightly better screen or a faster processor.
Also, the difference in price means you may exchange the laptop one year earlier and get the real benefits of the technology evolution in shorter cycles.
So, I would still vote for the MacBook Air in terms of value. Of course, value is highly subjective, especially if you totally detach it from price. If you just look at the benefits you get, regardless of price, of course the best product will always offer the best value.
