But I find it wrong, someone based on the {tu'lu'be'}, and some vague indications with regards to the nature of the rover, to go on and write something like {Soplu'be'}.

An expert should write as an expert; unless he/she write only for themselves. But if you are an expert, and are writing something which will be seen and read by other people, then you have to respect the readers and follow the damn rules.

I've explained this multiple times. The rovers -be' and -qu' do not always apply just to the single, immediately preceding element of the verb. Sometimes they get applied to entire verbs or even entire sentences. This is not explained in TKD; it simply shows up in canonical sentences.

Hoch DaSopbe'chugh batlh bIHeghbe'
Eat everything or you will die without honor. (PK)

This doesn't mean if you do not eat everything you will fail to die honorably. The -be' applies to the entire phrase batlh bIHegh you will die honorably.

There are other examples I have cited before; I don't have the time to find them again. Suffice it to say that Soplu'be' doesn't mean definite subject eats; it means one does not eat.

As for why you would say that instead of Sopbe'lu', I don't think there's a difference. Lieven tried to make one, but I don't believe Klingon gets that specific with its suffix ordering. At best, complaining that Soplu'be' doesn't follow the "immediately preceding element" rule marks you as a grammatical curmudgeon, and does not improve anyone's comprehension. yIleS!

-- 
SuStel
http://trimboli.name