Most of Shadow technology is easy to produce. You provide it someone for food, and it grows. The problem is: how to get it to grow without killing anyone. How to circumvent the Shadow programming, designed to create conflict. How to have chaos without suffering, evolution without conflict...
In the end, the technomages face a task I would not envy.
To redesign something created by those who created them.
To jump over their own shadow, I would say.
They may fail. It may be their passing. But with their numbers and abilities, they will surely last centuries. They will achieve great things. If they are lucky, they will crack the Shadow puzzle and continue their kind. Even if not, they will leave a legacy comparable to Vorlon additions. The technology they build and discover is priceless, and will become the basis for future technologies, even if there will be no future technomages.
And if they have any say in the matter, there will be future technomages.