I do this regularly (I am also in NJ). I usually add extra perlite and or bark mulch to regular potting soil and throw in a handful or two of compost. Works for me!

Over the long term it is not helpful. The reasons why can be obtained from reading this summation on how water moves through the soil profile in a container situation.

Container Soils - Water Movement and Retention.

There are newer versions of this but the information remains unchanged. As someone who has gardened extensively in containers for more than 25 years, both indoors and out, I can firmly attest to its accuracy and the validity of the information it contains.

I would agree adding it would not be helpful, but I would also add that if this is for indoor use, even if it worked fine for growing your jasmine in, you might be unpleasantly surprised at how many breeding pairs of unwanted visitors you'll be bringing into the house. For indoor use, I do love compost as an ingredient, but I only use large-batch compost where the giant piles will superheat the soil to kill off unwanted fauna.

When you mentioned adding dirt to potting soil to absorb water, usually home-center style mixes already absorb more water than is ideal for container soils, and you might be more productive trying to get your soil going in the other direction. :)

Not sure if I've made myself clear. This is not mixing soil with indoor mix. This was a huge pile of wood chips from tree service that has aged for several years. Some earthworms may have worked in some soil from looking at the compost. I guess the soil amount is very small.

My observation is that, the indoor mix with peat moss can dry out very quickly. We can certainly add perlite and other amendment to it. But personally I like to use aged compost than the peat moss. Compost is much coarse with the wood chip residuals. I believe it hold nutrients better than the peat moss.

I bought some potting mix from big box stores. The quality is much much worse than the compost I get. It is mostly composted wood chips. I can find some small stones in it. We have to buy the small bag indoor potting mix and it is much more expensive.