There is actually an objective reason for dating the provincial maps 125 (or thereabouts): it is at this time that the locations of most (80%) auxiliary regiments are known, as the majority of surviving military diplomas date from Hadrian's rule. It's not entirely clear why. By 180, most auxiliary troops had Roman citizenship (all after 212), so diplomas (which were certificates of citizenship), were no longer issued. Earlier, it is possible that diplomas were normally issued in paper form (unless the recipient specifically requested, and paid, for a metal one?), rather than as a metal tablet, and so were eliminated by organic decomposition. Also, before 107, the empire did not include Dacia and so was not at its fullest extent (ignoring the two-year occupation of Mesopotamia under Trajan). 

 Of course, the auxiliary issue is only relevant to the provincial maps (where we would show the auxiliary regiments) and not to the overall empire map (where we don't). Ideally, we would have the same map as 125 for 30 BC (Augustus start), AD 14 (Augustus end), 54 (Claudius end-annexation of Britannia, Thracia, Mauretania), 75 (new Flavian legions) 211 (Severan legions) and 284 (loss of Dacia and Agri Decumates). These maps would not take long to make, as most of the details would be the same as the existing one - the only substantially different one would be Augustus start (30 BC), when the empire was much smaller. 

 If you can reproduce Goldsworthy's graphics using Inkscape, then it really would be worth the effort to learn how to do it. Because then we could produce some really attractive maps of all battles, not just Strasbourg, instead of the ugly line-diagrams that we have to put up with now.  

 Your other projects look interesting. I trust that they will all be physical maps - I think we have traveled a long way from the useless political maps that you used to make! Tuo Andrea