The Al-Anon literature sometimes suggests that boundaries don't have to be barriers.
I'm not sure.
Type 1 boundaries
Type 1 boundaries are where I withdraw somehow from a situation, saying I can't or I won't. Withdrawal, sitting it out, non-cooperation, or disappearance necessarily produces distance.
Type 2 boundaries
Type 2 boundaries are where I request that the person stop doing something, start doing something, or do something differently. This necessarily creates an asymmetry: a caller of the shots, and someone whose shots are called. Every boundary has a cost, and costs are high, in terms of closeness. A concession has a price, and I have to be willing to pay the price.
Boundaries always create distance and erect barriers.
The Al-Anon madness is thinking you can have distance and intimacy at the same time. No. Pick one. Or pick somewhere on the spectrum. If you want to be very close to someone, you'll have to put up with a load of crap (and so will they). If you don't want the crap, you can't have the closeness.
You pays your money and you takes your choice.