Very occasionally, last-minute amendments are bad enough that they lead to me changing my position on a bill, and I'll tell committee members to vote no on the bill if an amendment passes. That's not likely to happen in this case; even if the bill gets weakened, I want the committee to advance it.
Most of the time though it's more along the lines of "the substitute has several valuable improvements, please approve it and then vote yes" or "amendments XXX and YYY strengthen the bill, please vote yes, but amendment ZZZ is bad, and here's why, please vote no"
Of course there's no guarantee my feedback will even get read, let alone listened to. Still, except in toxic party-line situations, most legislators do want to pass good legislation, and since I testified on the bill they'll recognize me. So some of them might read it and think about what I say
And legislators do pay attention to feedback in general. Even if their staff doesn't have time to read the mail before the vote, they'll still see the subject line.
So if you're in Washington state, please take action on HB 2599 and SB 6312 today or tonight!
https://pnw.zone/@waprivacy/116008105847711024