Is your feature request related to a problem? Please describe.
This isn't a problem, per say. More just quality of life.

Describe the solution you'd like
If CTOV could generate a config file similarly to other mods, that would probably be the most concise solution on the user end.

Describe alternatives you've considered
I've searched online for hours, though I may not be searching in the right places to be fair. I've checked Reddit, GitHub repos, and a bunch of Google searches over the past week.

Additional context
N/A

I may introduce configs for CTOV 1.21.

Is there any way to modify the spawn rates using datapacks for 1.20?

Confer the minecraft wiki on how to adjust structure frequency

Would it just be a matter of adjusting the spawn rate of vanilla villages and CTOV follows suit, or would I need to adjust the data specifically for CTOV's villages?

You can adjust vanilla village and CTOV will follow suit.

Hi, i've tried your suggestion and it didn't work in a flat world. Normal villages are affected but CTOV ones are not. I changed the settings through a datapack i made, it taps into "data/minecraft/worldgen/structure_set/villages.json", is this correct?

Read this wiki and this should solve your issues.
https://github.com/ChoiceTheorem/ChoiceTheorem-s-overhauled-village/wiki/Adjusting-village-frequency

Hey, it seems you may have accidentally copy pasted the 1.20 link to the 1.21 entry in the wiki.
The 1.20 version is incompatible with 1.21.