Ask HN: Is anyone else finding it impossible to use SMS in new apps?

I'm trying to prototype an app that uses SMS as a channel for inviting other users to events (similar experience to Partiful). This is what the experience has looked like so far:

I signed up for Twilio and got a local number

I build my Twilio integration and in testing I find that my messages are getting blocked until I submit a campaign for "10 DLC" compliance

I paid $15 to submit a campaign for 10 DLC compliance

Two weeks later my campaign was rejected and I had to resubmit and pay another $15

One week later my campaign was "approved" and I could start sending SMS

Messages start working, but some of them are getting filtered with a vague "Your message content was flagged as going against carrier guidelines" error

I reach out to support and a few days later they suggest some changes to my messages to comply with carrier guidelines

I make the changes and I'm still getting the same error

And now I'm kind of dead in the water. The prototype has been code-complete for about 4 weeks now and I'd love to get some users in to test it. I could fall back to email but since this is going to be targeted largely at mobile users SMS would be the best experience. I just didn't anticipate this level of friction to even just send SMS to myself to test.

Is anyone else having this experience? Are there any alternatives out there that I'm overlooking? Or is this just the state of things now?