Would you consider forbidden lore xenostech as a fair skill? It would be different than forbidden lore xenos which needs specialization by race, in that it would bit cover a race's history, biology, tactics, etc. It would just cover various types of xenostech and only their tech. So you could ID a device as eldar, ork, tau, fra'al, etc and possibly with multiple successes get some inkling of what it may be or do but the skill only covers tech of various races not an in depth analysis of a race as a whole.

Identification can be done with F.Lore(Xenos). The rest - it isn't here, but perhaps it should have been.

I'd give it perhaps "Tech-Use +0; personal experience" and maybe F.Lore(Xenos) as a prerequisite for +0 level, and "ditto +0, Tech-Use +10, Literacy (Xenos:whoever) OR Speak Language (Xenos:whoever) +0" for +10 level.

It should not substitute Make It Work and other requirements - most Orky gubbinz would not become more useful, but knowing what exactly mekboys can do may help sometimes, the same with a good chunk of Eldar toys.

So your skill would only work if you had a specific xenos race skill? Might as well just take the skill as is then. Now I like making requisites like tech use and possibly F.lore maybe Admech, but the whole point is to make a single skill that just covers xenos tech solely. There's no point to it if you still need specific race xenos skills.