The purpose of the rule should be to prevent a player from avoiding finishing the game by endlessly prolonging it, not by quickly submitting the technical result. The player needs to be given time to comfortably finish the game at any time. Moreover, with mutual consent, they can choose not to finish the game or agree to a draw.
It's always possible to start a game, for example, in the spring-summer season of 13 and submit the technical result in the next season when its results are summarized. During this time, it's not difficult to contact the opponent three times with a proposal to agree on a convenient day. If, for example, the game started in the first month and a half, it should be finished by the end of the current season; if it started in the second half of the current season, it can be finished in the first month and a half of the next season. 45 days would be the minimum, and I think that's enough time for everyone. Or, you can simply limit the completion time to two months.
There are specific advantages, as mentioned above. There are no disadvantages if you don't force a person into extremely strict constraints. I don't understand the point of abandoning a game. If you abandon it and leave Heroes for two years, it doesn't really matter what happens to that game. But if you abandon it, ignore the game, and then play with others, it means you still want to play, so there's a game; play it. What's the problem? The answer is obvious: I'm not playing because I don't want to lose, because I feel like I might lose, and that's probably unpleasant. The only minor justification could be when players have a falling out.