"Making it all fit" is the problem IMO. I can accept that some things are looser than others, and I don't get why that's so hard to do. The Defiant in Enterprise is brilliant work, and for the sake of revisiting something from the past in an immediately recognizable way, it was also the best creative choice I think was possible. The impeccable execution makes it truly something special. Ironically Enterprise is the prequel I'd love to see booted from the timeline, mostly due to factors that result from its inbuilt limitations, but craft like that elevates well above its context.
Evoking the very specific familiarity with the original series Enterprise was the entire point of that exercise, and it was masterfully done.
I don't think much of what Discovery did was executed well, nor do I think the purposes behind its design work fit well with a prequel series like it wanted to be.
Strange New Worlds wants its design to be immediately identifiable and evoke the original series, but also be cooler than you remember. It's also not a single scene, which means that 1) it has time to establish its own look and feel that viewers become familiar with, and 2) it has its own things it needs to accomplish. The set designs and costumes work perfectly within that role.
I feel that the nonsense of the Khan episode really does provide an escape hatch to explain the difference between how SNW and TOS kitsch look. Not one that logically makes any sense (why is TOS pre-Romulan-dickery in the first place? Was JFK still shot in the TOS timeline?) but exactly the kind of desperate straw certain kinds of fans are happy to grasp at. Logically that implies that there's another timeline that somehow exists in the Trek universe where Discovery and SNW happen but slightly differently and with cheaper and smaller sets and prettier ships. (Or did exist, since in the case of the SNW episode, the original timeline ceased to exist when the changes were made, unlike when the 2009 movies time travel nonsensed their adaptation by saying that both timelines existed simultaneously, as later confirmed by Kovich in Discovery.)
I don't understand why it's so hard for fans to accept that we saw a ball in one series and it was red, and when it appeared in another series it was blue, without invoking time travel or declaring one or the other not canon. Adaptational differences are a thing. There are times you indulge them and times you avoid them. That simple. I would prefer the show didn't throw people who can't understand that a bone. It's not going to make them any less pissy, it's just going to feed even more bullshit "it's all Trip Tucker's snow globe delusion" fan theories.
Even when they suck, like that grungy-ass Enterprise. I'd accept a "retcon" in that case by way of the ship getting new hull plating but only so that I don't have to look at it anymore. = P