Four cites.
Reading the first one, “Drake utilized over fifty writers of antiquity and scrutinized their main works through a UFO ‘lens.’”
This says nothing about architecture and construction used as “proof” of ancient alien contact with Romans. It appears to be putting together “UFO-sounding” stories from ancient mythology and saying they sound just like some extraterrestrial phenomenon.
The second cite says “This book is about the possible connection between Romans and aliens. It is a fascinating read and will leave you wondering what the future may hold.”
Certainly nothing mentioned about architecture or construction. Unless you can cite the book itself, I don’t think really addresses the OP in relation to the Romans.
The fourth cite is a book that “might be the most convincing and evocative rendering of an ancient society (in all its alien-ness and sometimes disgusting-ness) that I have ever come across.”
So, about the alien-ness of that culture in relation to ours, not about extraterrestrial contact with Romans.
The third cite is kind of interesting, in that it does deal with a large constructed piece of monumental architecture in the MIddle East. It seems to focus on a set of stones that formed the platform on which the Roman temple was built, though it mentions that many previous cultures had used the site.
So then at 3:27 of the video it says “But if the platform at Baalbek was constructed thousands of years before the Romans arrived in the Bekaa Valley…”
So, the most relevant cite here says that the Romans didn’t construct the megalithic “proof of alien construction” part of the monument - that the stones, in all their immovable, can’t-put-a-piece-of-paper-between-them majesty, were there before the Romans arrived. And since the people living there at the time were certainly more primitive and swarthy, it must have been ancient aliens who did it for them, right?
You had a previous cite in this thread about Ezekiel’s “wheel within a wheel” which, again, is more related to the first cite you give in your post - connections between ancient writings and our modern concept of aliens - and less about the OP which focused more on monumental architecture and construction. The “literary criticism” tropes of ancient astronaut “thought” generally aren’t given the same level of definitiveness in terms of proof, in what ancient astronaut literature I’ve happened to read, as near as I can remember.
So I’d still have to conclude that the OP idea “Ancient astronaut proponents don’t cite Roman monumental architecture as evidence of alien intervention” is not refuted by your cites.