What is "reasonable" when it comes to making requests in our relationships? Ask ten people, and you'll probably get about that many answers. The common refrain I've heard lately is that, while you can ask for anything you want, having expectations of compliance/agreement isn't good poly. Not sure if I agree.
Everyone retains the right to say no at any time, for any reason, to change the agreements, and that's just a free choice issue. Technically, that's true. However, on a practically applied level, having clear agreements that are followed-up on without being changed haphazardly is useful to me in my life. The idea that my partners could just yank the rug up from underneath me without discussion, or be surprised if I was upset if they didn't follow through with an agreement, is distinctly unreasonable to me.
Let's cut back to the idea of reasonable requests: For me, these are things like, "Safer sex agreements aren't changed prior to being discussed.", or, "We don't have loud sex when a child is present in the house.", or, "If I say I'm going to do something that impacts you in a specific time frame, I will either get that done in that zone, or update you if that doesn't work out as expected before that time frame has expired.", or, a personal favorite, "I will let you know as soon as practically possible if I make an agreement or plans within another relationship that may impact the relationship we share. Preferably, I'll strive to include you in that negotiation.".
For a lot of more independently-minded poly folks, that list may sound a bit unpalatable, and that's okay! They aren't my target dating-pool. I seek partners that find responsibility to others to be an aspect of intimacy and freedom that they gravitate towards. For me, being emotionally involved with someone who lacks an interest in having agreements with me is unpalatable. It doesn't lead me in the direction of feeling emotionally intimate, and comes across as a lack of interest in me as a person, much less as a relationship partner.
Perhaps this is a reflection of the relationship goals I have of "long-term" and "stable"? Typically, I don't get into deeply emotive relationships and just "see where it goes". Intimate emotional connection and vulnerability is reserved for those in my life who are positive contributors choosing to be integrally connected for the foreseeable future.
Does the concept of "reasonable" all boil down to mutual choice? This seems likely. Reasonable agreements are ones that are mutually beneficial on some level, and consented to in concert. Changing those unilaterally without arriving together at a new position isn't likely to build goodwill and trust in your relationships, so take the time and expend the energy on creating accord with your partners. Be reasonable!