How I would build on the PBE crit changes.

First of all no more RNG. It is unhealthy for the same reasoning that was used to remove dodge from the game. 1% crit chance will now be changed to 1% "weapon efficiency" which will increase auto attack damage damage by 1% of total AD. This stat like critical chance can not exceed 100%.

Zeal is reduced to 15% weapon efficiency from 20% crit chance and the items Zeal upgrades into are reduced to 25% weapon efficiency from 30% crit chance. This is to make the real breaking point for when armor becomes less effective by PD + IE be about 125 armor instead of the current PBE setup which is closer to 62.5 to better reach the stated goals of less damage to squishy targets or semi squishy targets and more damage to tanky targets which outside of the 10% higher crit chance from the IE + PD/hurricane/Shiv/rapidfire is actually being achieved with the current PBE changes. That extra 10% crit chance makes the new IE have higher damage output in any realistic situation where someone would have a completed zeal item and an IE.

2 completed zeal items will have the same damage output against a target with 100 armor between old and new IE reguardless of if the crit chance is reduced to 25 from 30% with the new being worse against lower armor and better against higher armor targets.

https://docs.google.com/spreadsheets/d/1qoDNOpodHbYjrrS6kpan1Y8YthpmaOIuPMpvilpOq9g/edit?usp=sharing

The IE changes go through as stated with one change being to the IE true damage system due to having to function in a similar way with the replacement to crit chance. "A percent of your auto attack damage equal to 20% of your weapon expertise is converted to true damage. Does not apply to on hit effects".

That is what I would change building on what Riot has posted on the PBE. It makes lower armor targets a little more sturdy from marksmen autos, makes armor stacking a little less effective, makes the systems have no RNG involved and also removes the increase in damage the new IE provides compared to the old one due to doubling 30% crit chance.