As regards simulations and the prior discussions of how quickly Taylor could catch up to the TSAB:
I don't know so much about other sorts of simulations but I could certainly envision them being mostly made by small research teams for funding reasons.
Magic is more important to TSAB civilization than almost any single thing-for-which-we-have-simulations; I would expect large investments in sim development until accuracy was deemed sufficient.
In general, yes, most simulators are built as hobbies or otherwise. The more common thing these days is various forms of virtualization, but that typically assumes it runs on the same hardware...in this case, building a simulation of the world is a much larger endeavor.
I think there is also a communications-based limitation on the size of a team building/maintaining a simulator, as it's likely that there are significant interactions between subsystems, so the practical limit is probably one or two people per logical subsystem. How many subsystems? I'm not sure, but probably a few hundred at most. Having more than one person investigating the same part of a given failure is (generally) a waste of effort, so that would also tend to argue for a smaller maintenance team, and quite possibly for a smaller team overall as well.
The TSAB might well invest in it, and other civilizations may have, but all we know is that Taylor and Hive have some mostly-complete simulator to work with, and the implication that Hive was a Belkan device of some sort.
Do remember that the Bureau doesn't have centuries of contiguous magitech development. The Bureau have what they managed to salvage after a devastating war, and labelled what they couldn't understand afterward as Lost Logia*... and not much else.
I won't say they aren't doing research and development that builds on top of what they do have, but even then it is, at most, around 150 years since they could focus upon stuff besides surviving and rebuilding; more likely less, given that the Bureau as it is is less than 80 years old as of StrikerS.
This links back to what I was noting with how much research Taylor could get done: assuming perfect parallelism, she's on average going to be able to do on average 84x as much research as a single TSAB researcher (disregarding memory partition), if she could focus everything on a problem. So, under that assumption, and ~150 years in which the TSAB or its predecessor organization(s) could focus on research instead of rebuilding, Taylor could conceivably catch up relatively quickly. Using typical man-hours for the 150 years on a per-researcher basis she could at worst duplicate that research in 35 years (assuming parallelism only as good as typical 4 thread memory partition); if there are better synergies, the number could be as small as 7 years per researcher. This is discounting Hive, who probably is closer to the 35:1 figure. This also depends on e.g. whether the 80-year number is more accurate for research, how large the initial research teams were, etc., but I think it's at least
possible that Taylor and Hive could catch up to a similar level in 2-3 decades, if not faster, given the effects of communication overhead (and that 30 years of multitasking Taylor is the equivalent of 16-32 researchers if there's no need for communications overhead or replication of experiments)...
So the big difference regarding development of any well-documented higher-level system would depend on how much of a common base Taylor has with what the TSAB would...my guess is that she has some significant chunks of Belkan magic (and the simulation system), plus generally better information on what the Shards do, so she's probably at a similar level of well-documented, reproducible, extensible magic as the TSAB, if in mostly very different areas. The other primary consideration is the TSAB attitude as to whether simply being able to reproduce the spell by different mages/devices is sufficient, or developing modifications and having complete understanding is the end goal.
