My local shop sells loads of Tropica soil now (over ADA), in their trial tanks, they measured minimal ammonia release ...
I decided to use Tropica Growth Substrate, then Tropica Soil Powder - Seachem Ammonia Alert exhibited the slightest shade of green after ~3 days, I did a 50% water change; I basically followed Tropica's App changing water every 3-4 days (I like to do 50% rather than 30%)
I added in shrimp & otocinclus from Day 1 as tank had been up & running prior to the rescape, other inhabitants were a shoal of chocolate gouramis which I've kept in an alternate tank until plants grow in (these fish are much more comfortable in a heavily planted tank & I'd used mostly 1,2-Grow plants).
At Day 7, I added in some brilliant orange guppy juveniles (~2cm) as I wanted something to watch
I've not detected any ammonia except at ~ Day 3, filter is obviously established but fish load has always been low.
After planting & flooding the tank, I did a 50% water change on Day 1 - to remove a bit of "scum" & slightly cloudy water - as no ammonia was detected, I added shrimps & otos back into the tank.
Soil was a bit "floaty" the first few days, a month on, it's definitely more "earthbound".
Plants have settled very well & I'm impressed with the growth, water clarity has been very good on this tank - when I've moved plants about there can be a "puff" of dust that clears quickly.
Now I want to swap out the substrate in my other tank