Boundaries are for you not them. This is something I took a while to figure out.
If you decide you want to relax them you can and you should without adding to your guilt and beating yourself up.
I initially set a boundary with my beloved alcoholic bride that I would commit to a future with her but my boundary was that I will not have active alcoholism or addiction in my home because it is not healthy for me or our son OR HER.
She got sober after I gave her an ultimatum of hospital or out but not home drinking 4 years ago. Back then, that was the right boundary FOR ME and for her. She lost her home, the man she loved and the life she dreamed of.
But that was four years ago when she was my very troubled and pregnant girlfriend. Today she is my wife and my best friend and I have seen 4 years of her working recovery and during that time my boundaries have changed and it was difficult when I told her that they had but I wanted her to know that I realize she is likely to have a slip or two in the next 40 years and I decided that first of all, I knew damned well that if she starts drinking tomorrow I will do whatever I can to get her back to her meetings and off the booze but I'm not kicking her out. I will let the situation - which may never happen - dictate my response.
I also realized that 4 years ago when she was going to AA to get the heat off of her the fear of losing everything was a strong deterrent. Today she understands and wants recovery for herself so it was more important, in my judgment, for her to feel safe and secure because fear of abandonment is one of her skeletons in the closet that screws her up and I would rather she knows I am all in. I told her that I could not tell her how many relapses would be too many but I knew that the next one, should it happen, would not be.
She's established her own boundaries. She left when my refusal to get help with my own issues caused depression and anxiety and was threatening her sobriety. God what a woman... anyway her boundary is that she won't live with a crazy person either.
Your boundaries are there for you, you don't even need to communicate them. You can alter them as your feelings and the situation dictates because if you are taking care of you then those boundaries will likely evolve with your increasing ability to accept others as they are and not as we might wish for them to be. If their misbehavior no longer makes you nuts, you needn't inconvenience yourself with an overly stringent boundary.
Stop kickin your own ass voluntarily ;-) If you set a boundary and feel you must go against your gut to stick to it then you are kinda beating yourself up aren't you?
The first person we have to learn to forgive and accept is us. Figure that one out and the rest gets easier (so I'm told!!!!)
Oh - and although I know the above to be correct and healthy it is one thing to know it and another to live it. If I listened to myself I would not be here ;-)