Well you could always pressure can it with no safety concerns except it would be a 'guessed' time.

For BWB canning it is "probably" safe with that much lemon juice but that's another guess. There is just no way to know for sure. And there is still the density issue to consider. It sounds like it would be pretty thick.

NCHFP has a Mango chutney recipe that you can add tomatoes to and use it as a base recipe. It already has the onions and I suppose you could sub some peppers for some of them but it is still a make-it-up-as-you-go-along recipe which is strongly discouraged in BWB canning. And it calls for 3 cups of vinegar!

So with all the guesses, the unknown pH factor, the density issue, and the no-cooking before eating factor combined, personally I would not do it. I'd make it and freeze it.

Dave