Okay, first, I have issues with this transliteration of “thalaron”, since Klingon lacks the consonant cluster “th”.

Who says they were transliterating? They just used a foreign word. It gives the sentences a certain je ne sais quoi.

Second, since you must be speaking from the future Trek Universe where thalaron and Remans exist In THAT Universe, your message might be read by a Reman, for whom the weapon isn’t alien. If the listener isn’t Reman and hears you say it’s a Reman weapon, of course, it’s an alien weapon, right? Why state the obvious? Why be so redundant?

"It's an alien weapon, used especially by the Remans" isn't redundant. The first part tells you that its origin isn't us, and the second part tells you who uses it most.

HIvmeH tlhoS tlhalaron woj lo’ rIymuSnganpu’ neH.

Or perhaps:

nuH lo’meH tlhoS tlheylaran woj wIv rIymuSnganpu’ neH.

Except it's not that only the Remans use it; they are just especially identified with it.

Or:

tlhoy Qobmo’ tlheylaran woj, lo'Qo’ HochHom, ‘ach HIghqangchu’mo ‘ej’ batlhHa’qangmo’ le’ rIymuSnganpu’.

Meanwhile, going back to the original, I think this is a weird use of the English word “especially”.

Yes, it is neither clear nor specific.

-- 
SuStel
http://trimboli.name