The game does a terrible job leading the player through act 2. Here is my feedback for changes:

The game does a terrible job leading the player through act 2.

The amount of non-ascended players asking for help with jamanra is... quite high.

Therefore the game needs to do a better job leading to the first ascendancy.

Currently the zone is semi-hidden and can only be accessed when they actually find balbala and check the table at the right time of progession, because the trial zone doesnt even show up right after they loot the first key.
Its just balbala having cryptic green text when they click their key, without any indication of where they need to go next.

Changes:
Make the trial show up as soon as the player loots the key, with a quest that leads them straight towards it. Make a quest for finding/killing balbala, currently she is just an extra boss-icon.

Skill gems level 9 have to become available at least 1-2 zones earlier than they currently do. If the players would have found at least 1 skill gem lvl 9 by the time they reach jamanra, they might turn around and farm for another one.

At least one lesser jewellers orb should be guaranteed before facing jamanra, maybe as a quest reward. Guaranteeing a jeweller and skillgem-9 drop from the first trial would allow the player to change their first 3-link if they did not like their choice.

During act 3 jewellers should become a lot more available to allow players free choices with their builds.

Damage calculation:
Honestly, just lie to the players about damage during campaign.

Buff it to a degree if it is too low (like a multiplyer when its below threshhold) and drastically lower it when it is too high (negative multiplyer above certain threshhold, say from *1.0 to *0.1 if the damage is really high [geared char or second playthrough, also balances build viability during story]).

After a certain number of deaths a boss or zone could even enter a "pity mode" with limited abilities or slightly lower damage/more (weaker) adds for flask charges, something like that.

Just some more thoughts:
The required zone level for each new tier of skill gems should be lowered by 1-2 level to give more chances of changing to a higher tier skill before facing a boss.

Currently skill gem 9 would be only available in the last 2 zones of act 2, skill gem 11 is only available during the last zone before viper and the molten vault.

I am sure that there are more examples of this for skill gem 5 and 7...