I'm not sure under what conditions it would start polymerizing - not something you want happening when it is inside your body - but yeah seems way too reactive. If it doesn't react with itself then perhaps with other materials. Probably not picky...
Although in this molecule there are conjugations possible, so it will be a terribly nasty polymerization. If you're gonna synth in vivo crapola, at least make a decent homopolymer.
It's a really obvious substitution, any time you see an allyl like in AL-LAD or 5-MeO-DALT, the vinyls must have been considered. Although granted there it's N-substitutions. Rarely you find something simple and brilliant that makes you wonder why it hasn't been done before. This is not such a time.
By the way if anything it approximates a psilocin / 4-MeO-DMT bioisostere, not one of DMT, even though it is an analogue / derivative of DMT. And since psilocin doesn't need a helping hand for oral activation, you would be left only with general RC novelty.
I'd rather just see them make 5-halo-DMT.