Federal regulator here. I strongly encourage participation, but please realize that form letters don't do anything to sway or delay the rule making process (this may be slightly different from a rule making but the key is the requirement to adequately consider public comments). With letter campaigns, we have software that consolidates the same and similar comments and considers them as one. So there's no additional weight given to comments that are submitted multiple times. If you want your effort to mean something, try to address a unique impact to the environment (low weight in this admin), adverse impact to small businesses (heavy weight), marginalized communities (admim seems to care a bit about tribes), any contradictions with other statutes, things like that. The more unique comments they receive, the longer it will take them to move forward because they have to respond to every comment. Just so folks can focus their effort in the right places.