Show elo you get after a game

I don't think is that easy due to all the requirements of the algorithm. First the algorithm is Whole History Rating - WHR (not elo) which takes into account all the games played at once. Then there are some extra rules applied on top of that to make it more "user friendly". For example because it looks at all players at once, your personal WHR can increase/decrease due to games played by other people (ex: you beat the 1st of the ladder -> that's big increase for your rating. But - let's say 1h later - then 1st of the ladder gets beaten by lot of players -> algorithm deduces that your rating should have not been increased by that much -> your visible rating decreases). As it is not intuitive to have WHR decreasing when not playing there was an extra "rule" that your visible WHR will decrease ONLY when you loose once. Same goes for winning BTW.

I think a lot of the problems is thinking about rating something you can "farm" (the more you win the more you gain) and that is "fixed" (can't change without you playing). This is not entirely correct due to the characteristics of the algorithm of taking all games into account.

Note: the above are mostly from what I understood on the implementation from various discussions I did not write or look at the code in detail, but the challenges/solutions make sense.

It doesn't really need to be implemented because you would just need to change to the old Elo system to achieve the wanted effect.
Whole History Rating is already based on Elo, but you can see it as a timetravelling rating system, so your rating now is not fixed and can change as soon as any future game is played by potentially any players.
However, if the game is played far in the future, it will change your rating less or if the players involved in the future games are not well connected to your games(imagine dividing the world into timezones where US player never play EU players for example) it will also change your rating less.
I like time travel. :D

The argument for including all games in Casual rating was that it has the best prediction rate.

I prefer everything visible (maybe do not advertise things much, but hide them deep in some links).

Before we had things visible admins were the only ones that could check some "invisible ratings" and it felt somehow not fair...