Mass IG DM to existing followers

Anyone know anything about best practices for sending mass auto DMs to your existing followers? Daily limits? Apps to try for sorting followers so that you message only the folks who are most active with you?

With FCC killing net neutrality (and IG continually lowering reach) I am trying to get as many of one of my client's fans to sign up for his text message list...that way we can market new songs, local shows, and merchandise to them directly without social media in the way.

Basically just want to send a non spammy DM (ideally personalized with first name or username) without a link that says, "hey ___, how are you? Trying to stay in touch with my listeners directly without social media in the way. when you get a chance, send me a text at xxx-xxx-xxxx"

any advice on the best software to do this with as well as daily limits, time delays, % randomization would be extremely helpful.

Couldn't you just add to your story? It's basically a DM that only your most active followers will read.

because ig owns the connection to your followers not you