I would assume they are collecting IMEI when they say device
aren't doing anything illegal particularly modding official apps, or using such modifications.
how is "modding" an app illegal?
I don't know if my Device ID with my real location would end up in the hands of a Data Broker(s) that would start profiling other data linked to my location to then sell it to other Data Broker(s), that's my only worry
Yes. Anything with "ID" in the name should give you pause, especially when its designated to you by the largest surveillance company on the planet.
You can simply delete it.
Settings --> Privacy --> Ads --> Delete advertising ID.
why do you assume that advertising ID=Device ID
I would assume they are collecting IMEI when they say device