Any point to flooding a "robo-answered" number?

Somebody is calling cell phones in my area, claiming to be raising funds for a police department in another part of the state. I haven’t gotten one of those calls yet, but a friend did. I’m 99.9% sure it’s a scam, because when I called the number that showed on my friend’s Caller ID, it’s answered with “Thank you for calling the fundraising center” like I’ve heard from previous shady police/first responders fundraising calls. The “robo-choices” when it answers always seem to be “press 1 to not receive future calls, or 2 to end this call.” In my unending quest to be a dink, I always press 3 or something else, and the call ends.
My assumption for why the supposed originating number isn’t totally spoofed is to give them some wiggle room to show that they did give recipients of their calls plenty of chances to “opt-out.” (And they didn’t spoof their number, so it must be legit, right? :roll_eyes: )
So would flooding that number hamper these bozos in any worthwhile way?

only if it overloads their system, or they’re using a toll-free number, in which case they pay for every incoming call

Thanks. I had one a few week ago that wa dumb eough to use (or leave in voicemail) a toll-free number.
I suspect (but probably will never be able to prove) that the’re actually calling from another VoIP number, and displaying the one my friend posted as a “decoy,” and/or as proof that they provided a way for people who wanted to “opt-out” to do so. (I don’t believe for a second that any scammer actually removes a number from their spam list, )