question

If you set "no virtual switches" and no assistants, no grid code, the MP will charge when connected to the grid and passthru to loads as you know. During this state, if you switch from anydevice between on and inverter modes, switching is instant without loss of power to the loads. Charging will automaticaly take place when "ON" and when you switch to "INVERTER" charging will stop.

No, that is not accurate. There are options available, but wether or not you implement those options of course is up to you.

Some other options for you to consider:

1: Conditional AC input can be done thru node red, and using node red you can pretty much design it to do whatever you can think up in terms of conditions to decide when to connect/disconnect. If you want dynamic control (ability to change the parameters) you can use node red dashboard to make changes on the fly from any connected mobile device or PC. If you want to be able to control it remotely, this can be done by accessing node red dashboard via VRM from anywhere.

2: A recent update to node red added two extremely useful nodes, Custom Input and Custom Control. These two nodes give you almost unlimited access to the entire dbus. Using the custom node, you can set the charge current to 0 in the inverter, essentially disabling the charger. You can also use this node to set any value you want between 0 and the maximum setting for the charge current. Same as with option 1 above, you can use dashboard to control the feature as well as access the dashboard remotely thru VRM.

Option 2 I have just tested in my own system and can confirm it will do exactly as described.

If these options don't fit the bill, then perhaps a little more info on exactly what the desired behavior is would help to steer you in the right direction.