How not? Cheogram is using xmpp, no? Just using jmp as a 3rd party service to give you a number. Right?
I'm hosting my own xmpp server to have better control over my data, ensuring the in-app texting is secure. Of course over a mobile number of a text recipient, they're still vulnerable to normal carrier bs and therefore so would my messages be exposed. But I think cutting back shows and potential to block the spam calls