Not to be rude, but did you even read my post beyond the first sentence?
I read your entire post yes. More reacts will not be added and the one suggested is already covered by the reacts I mentioned in my post. You mention that this proposed react would help with peaceful communication and reducing toxicity, however, if I voice an opinion and get thumbs down reacts but nobody actually tells me what the issue is it seems like dogpiling which seems pretty toxic. How will I know what the issue with my post is?
If someone you believe has voiced an incorrect statement its better to actually voice your opinion then to just "thumbs down" the post. This creates a conversation and is what helps people learn and gain insight. You shouldn't be afraid of clogging threads because healthy discussion is what Smogon is for. I see 0 benefit to adding a thumbs down reaction.