Brick pier replacement methodology / tips

Hi all!

I am about to start replacing some of the brick piers in the downstairs section of the house with 90x90 timber posts, in line with my engineer's design. Once the piers are replaced we will pour a concrete slab which we will then finish with a floating floor.

My question is as to whether anybody has completed a similar exercise in the past? If so, do you have any tips, or additions to the stages in the attached pdf which would provide a better / more durable end result?

Thanks for your assistance in advance!

Photo links:
https://ibb.co/F6jQDYY - Stage 1 - Existing Condition
https://ibb.co/K6vMNzB - Stage 2 - Post installed
https://ibb.co/sqf4tqd - Stage 3 - Slab poured