I'd add the leonardite and/or peat dusting on the bottom, deeper is better for Onxy.
4" or so is good.

Some add Osomocoat, some use a little soil etc.
You are not going to uproot much for the next few months, some it's not as critical as you may think.

You can plant and do a good job there etc, then do a water change to clean things up, but then do not do them later. Top off for evaporation only after that.

Pack the tank so that from the top view, you cannot see more than 5% of the gravel.
Yoyu can add SAE's Shrimps etc right away(1-2 days), and also add some zeolite and activated carbon to the filter(not required but will help).

I honestly do not care much for CRS's.
They are too small(food) to be kept with most fish.
Amano's are bad enough, these guys are even worse.
Cherry's at least breed like flies.

But neither cherries, bee/CRS's do much for algae.

Regards,
Tom Barr