Suggested

2 tyre compund per race

I think it would be nice if some interface could be added to the leagues where the league manager could "force" everyone to use at least 2 tyre compunds per race, since right now it's a gentlemen's pact of doing so in the leagues where people want to do it that way.

Could be interesting and maybe not so difficult to implement (I am not IT so I honestly have no idea about it)

Run 100% distance.

Leagues that run less are ss or soft fests,lol

There does need to be many more options for hosts though

League admin can manually implement this which many currently do. 
In my league I have multi tyre compound rule. So all teams must use any 2 tyre compound strategy in each race. For e.g. SS+S+S or S+M+S or S+H etc if it's a dry race. If it's a wet race then the mentioned rule doesn't apply so you can go full wets or inters or if mix conditions dry tyre rain tyre. This applies only to elite tier and pro tier. Rookies don't have to follow the multi tyre rule. If anyone don't follow the rule there is a penalty system as following. 
Strike 1- mandatory 2nd last lap pit stop as a time penalty. Strike 2- start on medium tyres and must run 20 laps on it. Strike 3- kick from league. You can rejoin the league but your car DP will be poor which is the penalty.

Downside is to check after each race the race results of each individual drivers strategies that they are abiding by the rule and applying correct penalties but I have been successfully been doing this for last 8 or so seasons. 

But an option in game would be nice.

Hi MS,

I understand your comment. What you are explaining is what currently happens in the league I am in too. But, as you mention, you have to check manually after each driver. 

Wouldn't it be simpler to have an interface (or a button) to just force everyone to do it? Much simpler for everyone, including the admin of the league.

Just a suggestion. Maybe there are other better ones out there about the game :)

Would be good to implement that all leagues have to run multi tyre compound. Notice in our league a lot just run H H. I try mix things up which sometimes work.