Multiple modern minor races (human and otherwise) had Iron Age civilisations before -100,000.  These include the Florians, Luriani, Sydites, Shriekers, and Addaxur.  Indeed, the Darrians apparently retained writing clear through from the days of the Ancients.  The earliest Vilani written records date from -22,000 (17,500 BCE), and trade between city states began once the Ancient juggernauts ran down, about 15,500 BCE - they were very much latecomers to the civilisation scene.

Sure, compared to the highly atypical Solomani, the Vilani progressed somewhat more slowly: about 1/2 to 1/3 the pace of the Terran progress from the industrial revolution onwards.  But compared to everyone else, this was a lightening pace.  (Once again, a comparison can be made to Chinese technological advancement, and stagnation, compared to the West, and the fascinating debate about how this divergence came to be so.)

And the progress from spaceflight to STL interstellar exploration (200 years), and from jump drive development to interstellar expansion, was even more rapid than the Solomani progress at these stages.  Technological change only slowed once interstellar expansion gathered pace (it was more profitable to expand into vacant territory than to invest in risky R&D), and then froze once there was a complete suppression of any competition (both externally and internally).

Much the same trajectory was followed by the Solomani: high-pace technological development when survival depended on not being behind the neighbours (1800 CE through to the Interstellar Wars), followed by a prioritisation of investing in geographical expansion into the old Imperial territories over investing in R&D.  

Bottom line, the Vilani technological trajectory - until the conscious decision to cease issuing technology patents - was well within Terran norms.  I can see late-Ziru Sirka _individuals_ experimenting and being curious as all people are, but there was no point in trying to profit from the fruits of such curiosity.  The fetishistic neo-Vilani "curiosity as sin" may well be a product of Long Night-era Vilani looking back on the "glorious stable days" of the late Ziru Sirka, or even a Rebellion-era reaction against the wider Imperium to justify secession.  After all, Vilani megacorps managed to hold their own against Solomani-dominated megacorps in the marketplace of the Third Imperium.

Now if you want _fast_ advancement, the Geonee went from developing agriculture and writing, to colonising their stellar system in 4700 years, with a "volcanic winter" causing mass extinctions and "near-collapse of civilisation" about 2/3rds of the way through this period.  They then developed jump drive a few years before the Vilani.  How in hell did these bad boys lose to the Bureaux???