No, but given Justinian’s logistics versus the newly established powers in formerly Roman lands like the Gothic nations, I’d argue that his conquests were too big to work the way he wanted in the specific time period.
But that's the point, Austria and its associated domains were very peripheral to Spanish interests and forced Spain to play a different game, so they were recognized as a liability and spun off; most other historical gains simply were a bit too much of expansion in a desirable direction, but their 'too much-ness' became only apparent after a while and often still helped protect other, more integral areas, from direct threat.
The African colonies were still important for the empire; while they were a net loss in terms of state revenue, they made a lot of other people a lot of money. Cocoa, coffee, cotton and other cash crops like palm oil and rubber could be grown there on the cheap and sold with a huge mark-up across the Empire. The Euros really shot themselves in the foot through their great ignorance of traditional farming methods - the colonies could have easily produced far, far more had they actually bothered to consider why the natives wanted to do things differently.
The SPQR was build during a climatic warm period when conditions were favorable for urban, agricultural state-societies. Hence these kinds of societies boomed during Classical Antiquity in Europe, becoming huge and incredibly dense. By the time of Justinian however, changes in the global climate caused a cycle of macro-economic decline, which led to the collapse of urban centers throughout western Europe. Economics of scale really disadvantaged big, expensive conquests and centralized states in this time and place.
I personally agree with most of it. Keep France on the so-called natural borders, plus Piedmont and Liguria.
