Simply put, will continuously simmering vegetables for days, even up to a week or two, in a perpetual stock lead to unexpected or unwanted results?
Since even the longest stock recipes I know don't take more than a day to make, I assume flavour extraction will stop after a few hours but does cooking veggies beyond that point generate off-flavours?
I've also looked up safety concerns of perpetual broths; in this case, since it's a vegetarian one consistently kept at a simmer to which I will regularly add boiling water, I don't think it will be an issue. I'm still new to food-science though so I might have missed something there.
Some answers, for example this one by barbecue or that one by jeabp, partly answer this question, however, I don't think it's specific enough to render this one a duplicate.