Funny and amusing situations...

Turn-based games are indeed more demanding. Just look at the turn transfer speed – in turn-based games, this process takes about twice as long.

I thought so too. But then Samurai started insisting, so I decided to measure it, and here are the results:
- initial loading: the unpacked save file in SOD is indeed smaller than the VOG, but the packed VOG is about the same, the difference is 5%-10%, 20-40 KB, i.e., a very insignificant difference
- therefore, during the transfer, you see not the transfer time, but the unpacking and parsing of structures
- during the turn in VOG, nothing changed, i.e., the requirements clearly did not change here
- turn transfer, only changes are sent there, so nothing special, although the transfer of the first turn may be slightly heavier...., because it seems that the second player does not have a VOG-ified structure... but this is not certain and not significant

Therefore, if there is any empirical bottleneck, I cannot understand its cause at the moment.