The XST whitepaper was reviewed by some of the bitcoin core devs and they came to the conclusion that it was unfeasible.
The least you can do is be truthful. They didn't say it wasn't feasible and in fact one of them said they didn't have enough information about all potential solutions to actually know or not.
This whole thing is just pathetic. Both sides just spewing off bullshit to suit their own purposes. Grow a fucking spine people and show some ethics in what the hell you say. The number of children in this shit pretending to be adults just pushes me over the edge at times.