Probably I misunderstood your needs.
I really did not understand what you are trying to do, it's really hard to help you. I'm trying.
However please believe me, you don't have to reverse engineer anything. There is absolutely nothing hidden.
Look, it's really easy...
PF rules are structured in anchors (=folders) and rules. Murus creates a complex ruleset made of rules and anchors. This ruleset is made of a bunch of files in /etc/murus and is read by the 'pfctl' command. This command reads the files and loads rules in runtime. That's it.
Using Murus you have the runtime pf browser. Please use it instead of the terminal. You don't need the terminal, Murus displays all the information you need. By default pf browser shows you rules in pf root. In the default view it tells you current pf path in toolbar. You change path double clicking an anchor or clicking arrows, to display its content. PF browser allows also you to choose the tree-view, so you see all rules in the same view, just click the corresponding button in the toolbar. You don't need any specific knowledge to use this thing
From the shell, you just have to look at pfctl syntax. Again, there are examples in Murus manual and PF manual.
For example to display rules in /murus.inbound anchor you type
AND: After a machine reboot the problem in this thread disappeared by itself ... anyway I do not think it is a good think to reboot a machine to get things running ... isn't it ...
You *never* need to reboot your machine when using Murus and changing pf rules. You just have to read documentation about stateful firewall, pf states, their persistence, the effect of their persistence, and how to kill them.
I did not (yet) reverse engineered the nice anchor system, I thought I could avoid it
Please understand that Murus is a front end, there is absolutely *nothing* hidden, and nothing to be reverse engineered
The purpose of Murus is to create plain text configuration files for OS X built-in pfctl shell command. You find them in /etc/murus and you can see all runtime rules using the pfctl command (and its many options).