M.M.
Hey E.,
I don't have tons of experience with this, but I wanted to share something a co-worker shared with me.
She has three boys (all grown now). She said she completely stressed about the eldest getting potty-trained. When the second came, she decided she wouldn't go through that again. Same with her third. What she did was this: she told them what the potty was all about, read them books about the potty from the library, had them watch her use the potty, told them they could use the potty whenever they wanted and that was it.
Her second child (a girl) announced at 2 (almost 3) that she was done with diapers. From that moment on she was toilet trained. Her third child (a boy) announced the same thing at age 4. And just like his sister, he meant it - he simply transitioned to the potty overnight.
She said the hardest thing was dealing with relatives who couldn't handle her laissez-faire attitude. Otherwise, it was completely stress-free for her!
So, I don't think you're holding him back. Good luck. M.