coz its anomalous
My headcanon on the whole "why the foundation doesn't use magic" question boils down to this, and I think you'll find its a pretty common view. Its not just a safety thing or a lack of understanding thing. They've spent over a hundred years caging and studying some of the most dangerous mockeries of reality imaginable. They know all about magic by any name. The proof is that they do use magic now and then, and on grander scales than any known project undertaken by any GOI. Those uses are the Thaumiel items, and they are considered every bit as dangerous as any other SCP.
Compare the GOC and the Foundation. The difference isn't just destruction vs. containment- its where they draw the line, the standards they hold themselves to, and their end goals. Where the GOC sees good magic and bad magic, the Foundation sees arbitrary distinctions made based on what is convenient for the GOC.
Where the Foundation was founded to pursue answers and preservation of both the normal and the anomalous, the GOC was founded on rage against the occult. The GOC fight fire with fire, and don't care who or what burns along the way. They frequently make things worse by thinking that knowing how to do or destroy something is the same as understanding and having control over something. Ultimately the difference between the GOC and the things they hunt is that the GOC has uniforms and helicopters.
The key to the Foundation's attitude toward magic, on the other hand, really gets down to the Thaumiel items being SCPs with their own containment procedures. To the Foundation, magic is just like radioactive material. Used cautiously and sparingly in carefully engineered situations, it can be a powerful tool. Set loose without control, it does harm to everything it makes contact with and is capable of leveling cities in an instant. They have hundreds of SCP files proving it. The Foundation doesn't use magic in the field for the same reason armies don't use tactical nukes: the advantage simply isn't worth the cost.
I'm not saying you can't do something like this, mind you, but you really need to address this side of the argument. By any headcanon, the Foundation using magic means they are unleashing the exact sort of thing that they spend their entire lives caging. They've made that mistake once before. It ended badly.