chop and drop regrets

I was asking the good and wise people of permise  what mulch they prefer for the veggie garden, (Which mulch should be used in the veggie garden?) and Ann Miller suggested living mulch, and I thought that was a super idea.  I have been trying to decide what to plant.  I thought it would be a win win if I could chop and drop it as well.  It got me thinking, and I wanted to ask if any of you planted something for a mulch, or for chop and drop purposes, and had regrets, and why.  Example I planted borage.  I don't really regret it, but when I talk to people about it I make sure to tell them it will reseed itself all over.  Unless you are very careful, at least where I live once you plant it you have it for life.  I thought it would be useful to know what I should avoid, or at least take extra care with when planting.  Thanks

Good question. I'm personally very tolerant of wayward living mulches, but I did find others in my communal permaculture garden were a bit more bothered by plants going out of the bounds we planned for them. Borage was one for the same reason you described. Strawberries were another. I guess the important thing is to know before you start what you and other stakeholders are comfortable with in terms of plants that seed or spread freely.

Comfrey. Not a regret as such, but one you plant it in a spot it is there for ever. Mine produce great quantities of material with minimal effort - literally slash it back two or three times per year.  But keep it away from any area you might want to cultivate.

Swiss chard. It grows like weeds. Not the worst problem ever, but if we have another meal from it I might puke. I am not going to let it self seed ever.
Mint is another one.
Bermuda grass (dont judge me please, it was my first year into permaculture)

I don't have any chop and drop regrets.

I just wanted to mention that clovers are the best living mulches reason being that they protect the soil from wind and erosion. The clovers will work hard to improve soil health. Besides being a great living mulch the clovers will attract pollinators and beneficial insects.

I only have experience using winter rye on our lawn where we used to live.

I have a huge population of snails and slugs, and chop and drop just encourages them. It took me a long time to figure this out. (I did discover that drier mulches are not as hospitable for the snails and slugs, but are great habitat for the spotted beetles that destroy my beans. Sigh).