I think people are kinda overestimating the degree to which Alric will mess with us about this, because like. Let's look at the goals here.
Alric's primary goal is to re-secure his old over the Light College. His main way of doing this is through doing a Great deed. Now, the waystone project would count as that, except it's one with an undeterminable amount of time. He could be stuck here for up to 50 years before he get's an amazing results, all the while Mira is gaining more power over in the main collage itself. Alric is on a time-schedual as Mira is constantly moving around him all the time.
The waystone project while amazing, might take a really long time, which is why i think that muscling in and taking over the waystone project isn't something he'd be that interested in. Because it wouldn't give him results quick enough that it could matter to his goal of securing his patriatch seat.
Secondly, it's running into the issue of actually aquiring controll over the waystone project. As been stated several times allready, the elves were here for the assistence of Matilda, The dwarves is doing this as a favor to Matilda. The Kislev people are again on the request and favor of Matilda. Every single party except the elves, are as a result of Matilda action and favors. Primarly the human corresponder they are going to be looking for is Matilda.
The only guys whom Alric might have a chance to win over is the Lights(Which with Egrim in them, is unlikely) and the Jade collage, whom probaly would be having a slightly jaded look on this outcome. While it's still possible for Alric, he'd be using up a lot of political capital and fight, in order to secure the seat as the leader of the collages, for an project that again, isn't gurantied to succeded or be that quick.
I can't really see Alric being that vastly interested in the project simply because it would a ton of effort, in order to do something that might not even give him the results that he wants. There's plenty of deamons and mysteries out there that need solving, that is way more secure for Alric.
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The second reason Alric would have to mess with the project is spite against Matilda. Now, while i don't think it's entierly unlikely he won't be looking for ways to mess up Matilda as revenge, i don't think the waystone project would be the place where he'd do it.
Alric have generally been portayed as someone who while self-serving and arrogant, does still loyally serve the Empire. If Alric sinks the waystone project, that means the empire would lose their one big chance to understand how waystone works and potentially fix them. He would be setting the well-being of the empire itself in order to screw Matilda over.
And that's gonna blow back on him as well, because he'd be annoying the Ulricians whom are vested in the alliance, the dwarves due to being a part of the project, the elves(though they aren't that important to empire politics atm), as well as the different Colleges who are a part of the project now, atop of the chance that Alric is meddling in the affairs of other colleges out of spite.
Which would considerable reduce his own chances for re-gaining proper controll over his seat in the light collage. It's not immpossible, but i think it's highly unlikely, since it would be going against both Alric's goal of securing his own political power as well as his own loyalty to the empire.
Which is why i don't think Alric is that big of a threat. He isn't harmless, but i don't think he'd sink the project in order to spite Matilda, and he stand more to lose by trying to muscle his way into the project.
Personally, i'd consider Ulthuan the biggest risk to the project(beside the obvious Chaos) as it currently stands. Since we allready established how the Elves got mad at the ice witches for using the waystone project to benefit themself instead. If the Elves let this project fly through, they may be looking at a repeat of Kislev with the Empire creating it's own closed network, which to be fair, Matilda was thinking about.
It would that Ulthuan as a whole would have considerable less pull on the politics of the empire, since they can't monopolize the knowledge of waystones. Though, if this is big enough to make them consider manipulating affairs, i'm unsure on.