This article was based on a mixture of fact from serious academic books and original sources (I have done a complete chronology of the Roman Empire based on the original Roman sources, pub by Continuum/ Bloomsbury in 2010 so I am familiar with the material in detail here ) and evidence-based speculation. Also my first introduction to this period at the age of around 11, UK children's history fiction author Rosemary Sutcliff's novel 'The Silver Branch' (pub 1957) which covers the usurpations of Carausius and Allectus and Constantius' campaign of 296; school libraries don't seem to have that sort of enthralling novels any more, apart from a few children's Roman thrillers.
The bit about the Great Library in Alexandria and the move of scholars to Nicomedia, the then E Roman capital (on the Sea of Marmora east of Constantinople) is my own guess , but based on logic. I have tweaked the events in Alexandria from OTL to make the revolt and destruction less lengthy traumatic; this siege and the razing of the Brucheum quarter is one episode which historians have speculated damaged or wrecked the Library, destroyed some of the irreplaceable mss there, and dispersed its scholars. Another scenario for this is the revolt in the city and massacre by Caracalla in 215 - which I have butterflied out of existence too. This is deliberate and means that more ancient scientific secrets, original plays etc will survive to later centuries , speeding up development from what actually happened in the long term.