You’re coming across just fine. You’re just a person asking a question. (And, I think you have got your answer!)
This is the First Wives Club jumping in and burning you to the ground. And, they’ll just get worse and worse until you admit “defeat” or their comments get deleted.
This conversation has transitioned from “what would the court say about an edit to a court order” to “your SS doesn’t like you, your DP is lazy, this is all about money and I’ve assumed you’re definitely pregnant”
They are just warming up.
People forget that when you enter into this new world of step-parenting, it comes with challenges, rewards… and a whole new vocabulary! Until I met my DH, I’d never heard of “CMS”, “Court Orders”, “EOW”, “NRP” etc etc.
I didn’t grow up with it and I’d never encountered the world of separated families before. So, you ask questions and you Google things. You don’t want to be a passenger in your own life. You want to be involved! But they don’t take kindly to that attitude around here.
If court orders can be made, they can be unmade, right? Seems obvious enough and surely happens every day. But when you’ve been around the wheel a few times, like a lot of these women have (myself included) you understand that they can’t often be changed, unless there’s a very serious reason to reduce or increase either parent’s time. Status quo is very important to the courts.
There is no agenda to my advice. I’m second wife to two SC, one of them is the same age as your SS.
We do 30/70 and his ex tried to have CO reduced to 3-4 visits per year… she got nowhere and the CO remained exactly as is. We would like ours more too, of course! DH tried for full custody at divorce due to mother’s addiction. But court said it was in best interests of children to be mostly with mother whilst in nappies and it has remained.
We have talked a lot about attempting increases over the years. My DH works from home always on his own business, so childcare is straight forward for him. And I would support him in anything he wanted for his children. But we don’t think it’s good for the kids.
We moved house recently and every time we mentioned our “solicitor” my DSD would ask her dad about it. I think the poor little thing has PTSD surrounding that word.
The open door policy advice was sound advice. They morph as they hit secondary school, and then you might have him hanging around twice as much anyway. 
I’ve blathered on for long enough. OP, you have your answer. Don’t keep engaging.