Oh Christopher this is important.
Before you go to explain a change between Enterprise and TOS, make sure JJ Abrams doesn't contradict it in his next movie.
The Romulan War books kind of had that problem and I hope your book doesn't run into it too.
1. Do you really think he needs us to tell him to avoid that whenever possible?
2. I have no idea what you're referring to in the TRW books.
TRW made the rather stupid move of trying to explain the difference in look between Enterprise
and The Original Series
as a literal in-universe technological downgrade (because primitive systems weren't suseptable to the Romulan telepresence thingie)
This was already contrary to "In a Mirror, Darkly", where the TOS-faithful USS Defiant was seen as incredibly advanced and futuristic, but was also contradicted in JJ's Star Trek
, which updated the look of Trek's 23rd century, making everything look like anything but a technological downgrade relative to Enterprise NX-01.
IMO attempting to explain the ENT-TOS visual downgrade was ridiculous to begin with (especially in a nonvisual medium like literature!). The Gorn is a fearsome intelligent monster, not a guy in an obvious rubber suit. That doesn't need explaining. Similarly, the 23rd century USS Enterprise is an advanced futuristic starship, whether it looks as it did in 1966 or 2009.