Throughout life, one is reminded to acknowledge their limitations and work within them in order to both have the maximum chance of success and not make your task an inconvenience to others. It can be difficult to translate this into your polyamorous relationships when one is constantly being reminded that love is infinite. It makes it seem as if you can have all these deeply emotionally entangled relationships which simply just work because you share this common ethos of limitless love.
I do believe that a person is capable of loving many people and there isn't an inherent limit on how much they can love one person. I'm not sure love is quantifiable in that sense to begin with. However, what had become overwhelmingly apparent to me is that the fact resources like time, money and physical space are finite means that this does have a direct effect on what you're able to realistically offer the people in your life without having to sacrifice any existing commitments. This, in turn, affects the liklihood of a relationship becoming long term, the level of emotional and practical entanglement and overall, the level of expectation and obligation you build in your intimate relationships.
When people aren't aware and working within their limitations, especially during New Relationship Energy, it's easy to both neglect your existing commitments in order to have the resources to deal with these new demands and create a level of expectation in a new relationship that simply isn't sustainable over the long term. Not unless you scale back or shed some existing commitments. Be they people, hobbies, children or social activities, something has to give in order for you to meet these new demands. This can be why some people who have the intention of a polyamorous relationship style slip into something that more closely resembles serial monogamy: every time they start a new relationship, it seems to have a devastating effect on the existing relationship and that partner eventually opts out altogether. To prevent this, one must objectively assess what commitments they have in their life (and want to keep), how much resources it will take to maintain those commitments, and finally, what they have left for commitments they'd like to make.
It's also about compatibility though. It's all very well considering what you can offer someone new, but you have to find someone who actually wants what you can offer and nothing more. Not from you at least. If your commitments mean that you'd be able to see an additional partner twice a month or so, it would probably be unwise to pursue someone who is monogamous leaning and is looking for a life partner to plan a shared future. It's just asking for trouble.
Similarly, that new person should recognise what this proposed relationship can realistically offer them and ensure that they can work within those limitations and are comfortable with getting additional needs met elsewhere. Building a relationship without acknowledging these limitations can lead to you being resentful of their existing commitments, be they people, work or hobbies. Resentment, especially of metamours and family, needs other negative emotions and simply isn't conducive with healthy polyamorous relationships. As much as I find polyamorous philosophy can be couple centric, I also feel that "thirds", "solo polys" or whatever else you want to call a person who is the potential or existing additional partner of their paramour, are often alleviated of any responsibility for the relationships they have. It's as if they don't have the accountability that others have for finding compatible partners who are able to meet their needs.
At this time, at least, I'm not able to develop another relationship that has the same level of emotional entanglement as my current relationship. I'm okay with that.