Scheduled Google Messages a thing now
As with all things Google, this may work for you now, it may not. No amount of downloading different APKs will change whether it works as it’s a server-side switch, but Google Messages appears to now support scheduled sending so when you’ve got that brilliant idea at 2am you want to send to your light-sleeping on-call 24/7 friend, you can schedule it for the morning.

I mean, you could have always gone for email, but that would have been too hard.
This is in Google’s Messages app, which should not be confused with literally every other texting app called “Messages”. Scheduling seems to only work in the app, and not the web interface to the app as well.
To see if it’s working for you, pick a contact, type a short bit of text, and hold down the send button. If it pops up a schedule to send, it’s working. If it doesn’t, it’s not.
I noticed last night that I started getting errors with Messages that it was unable to connect through WiFi, and was using cellular data again. This tends to happen every update they do to me. Let me know if it’s happening to you.
So, RCS, scheduled sending (which I believe we had before they removed it for some reason,) web interface with ability to send pictures… acceptable.