Built-in autosave feature (for the TE version).

1. Or maybe in the first few days, while simultaneous turn mode is active, it shouldn't be enabled, but, for example, so that you can control the neutrals after switching to turn-based mode? This would even be better from the point of view of NOT peeking at the starting army and the opponent's setup – so they don't take restarts. And from the second week, you can already meet the opponent or estimate the army after a few taverns, etc.

Quite an interesting idea.

2. Given the answer to the first point, I think knowing the opponent's army from the second week won't be so critical, especially since the map itself remains hidden. In this sense, if it is planned to enhance secondary skills, the scout skill can be enhanced by viewing the enemy camp. For example, a hero with the scout skill, if he is in a city where there is a tavern, replaces the number of taverns = the level of the scout skill, or it can be tied to the hero's level, so that a level 10 hero with the scout skill is better than a level 3 hero.

Well, it's basically the same as with an open map.
You can see:
1. The territory where the battle takes place – you can roughly (and often very accurately) orient yourself where the opponent's hero is on the map.
2. Seeing the army you control, you will understand if the opponent is searching the treasure or not. And if you control a strong army once, it means you have just taken something worthwhile.
3. By controlling the crypts, you will roughly understand the opponent's financial situation, seeing him in the utopia... well, it's clear here, any battle after the utopia will show approximately what he got (he is unlikely to remove combat artifacts).

P.S. In my opinion, if the goal is to improve gameplay & balance, then such things should be a priority.
And simultaneous turn and timers are more about convenience. But ideally, I would like both.

The idea with the neutrals is quite interesting and it would be nice to try it.
But first of all, I want to implement all the interface features that will significantly reduce the game time, and then we can seriously deal with features that change the gameplay.

For example, in the next version, I plan to make the following feature to speed things up:
- before each battle, you are shown the result of a quick combat
- you can agree or replay manually
This feature is designed for battles in which you will definitely not lose anything (a powerful army, you are beating weak units), and they take about 0.5-1 minute.