The whole thing is that we didn't know about Waystones manufacturing and using Dhar as an essential component (which is different from just sucking it out of the environment and dumping it into the Vortex along with other magic) until Sarvoi brought it up. Once we have that insight, it really isn't hard to deduce that Waystones occasionally create Dhar when there isn't any to be absorbed, but most people in the Empire do not have the insight.
And it's less Algard and Dragomas in particular we don't trust (besides, we can always specifically inform them later), and more that the more people who know in general who don't specifically absolutely have to know, the less secure a secret is. The advantage Imperial has over College is that we can tell things to uninformed people we want in the know, but we can't take a secret back from someone who was informed that we don't want knowing.
We should be keeping secret the fact, that with sufficient knowledge Waystones could be used as automatic Winds to Dhar converter without clogging/breaking/corrupting. At least until we learn more about them.
But Waystones are not the
only possible Dhar-creating machines. You can make one by having any mechanism draw in any wind and then injecting
Dhar to kickstart it. Winds are so prevalent that it takes Dwarves some actual effort (and Runecraft) to make a single room devoid of all Winds. And creating
Dhar is trivial for any spellcaster: Any wizard capable of casting anything beyond that simplest cantrip can do it by simply drawing on two different winds. Wizards being mono-wind focused has nothing to do with being able to channel only one Wind, it is because they are able to channel only one Wind
safely. At the start, Apprentices can flit between the Colleges to try and see which Wind they suit best and they can do this safely up until the point they have their first Arcane Mark. After that, using any other Wind has those aspects clash in the wizards soul, creating internal
Dhar.
So I don't get why Dhar-producing machines are somehow such a fear: Any Magister worthy of the title probably could, if they desired, come up with one relatively trivially.
As for keeping this completely secret, we practically speaking can't.
Pretending ignorance is a very short term solution, or leads with the whole project group being declared Enemies of the Empire.
Every other human wizard in the project would either instantly know or soon suspect we're running afoul of Article 7 anyway and
that we as the project head are not informing our superiors of it in direct contradiction of procedure.
So then soon we'd be faced with the same choice but with no chance to pretend further ignorance, at which point we have to inform Algard/Dragomas or the Emperor (and thus Dragomas) anyway.
Or we choose to keep the secret even then and that would mean us having gone rogue and being guilty of an Abominable Act. At that point, for the rest of the wizards it becomes a matter of their loyalty to the Colleges and their loyalty to the group, on if they put this in their own reports or not (or even attack us outright as required by the Articles). Essentially making them too guilty of the same Abominable Act if they don't turn on us.
As I said, the project group now knows it or can easily deduce it from information already presented.
So we'd be keeping a secret from Algard and Dragomas.
For what purpose?
They don't need to spread that information forward, and in fact the only reason why we'd need dispensation is due to the Dhar aspect. All they need to do is inform the rest of the Colleges that:
a)we're studying Waystones
b)there may be potential Article 7 implications involved as part of the research (no further details necessary)
c)and that the Waystone Project group headed by LM Weber of Grey College has been cleared by necessary authority to continue the project.
The very act of requesting for dispensation already tells them that
dhar is involved, which given the function of Waystones is not a giant leap.
And anything dealing with multiple winds (without being High Magic) can be turned to
dhar-creating purposes by simple virtue of forcing the winds to interact.
So to me it seems keeping this a secret from Algard/Dragomas would be keeping secrets only for the sake of keeping secrets. But both of them understand operational security and have no need to tell forwards any real details.