When you use this, especially with mods.

Does it take into account the normal distrubution amounts of each resource, or just use the same base amount for each?
As in, in vanilla, you get way more iron and copper than stone when each one is on default settings. Does RSO inherit those differences? And is this the same for other mods that add new, differing ratios of resources?

Also, do richness/frequency/size effect RSO in roughly the same way? As in deeper/more common/larger deposits?

Sorry for late reply I missed the thread.
There are different base amounts per resource and they should be roughly same as in vanilla. Random distribution will affect actual ratio quite a lot since ore fields are more scarce with RSO.
For mods that add new resources they have configurations in RSO so it depends on how the resource is configured. They will have different ratios/rarities etc.

Richness and size affect RSO like you'd expect. Frequency is used by it works differently in RSO - it will affect relative rarity of given resource compared to other resources. So if you set all to high frequency nothing will change, but if you set iron ore to high freq and others to low you will have more iron ore patches then others.