every fish has its own personality and sometimes we can get lucky, but i dont think it extends so far as to have a Convict in a tank with neons...
even if the convict doesnt have a few fish for lunch as he gets bigger, and even if he doesnt act so aggressively he just plain kills fish, he will most likely want his own space in the tank, and with the fish you mention, they are so active, they will intrude in his space and even if he doesnt kill them or terrorise them to death, he is likely to stress them all out
not worth it in my opinion
i have all the fish you mention by the way, they all in the same tank (apart from my Convicts!)
it would also be a completely alien environment for him, so even if he didnt cause any aggro, he would could well be stressed (thats just my best guess)
I thought i would try and give my take on it, rather than just reply "no" which is what i feared my happen, the answer is "no" pretty much, but its good to discuss why etc......