Multiple NVL windows at the same time?

[Xinoel]

Hello everyone. I'm new to Ren'Py and not quite familiar with Python, so apologies if the question is basic (or weird).

Here I'm making something like a messaging system, and I want to put two NVL windows side by side on screen and let them just stay there like the player is talking with two guys simultaenously, with every dialogue popping up in either of the window according to the Character and doesn't disappear. Turns out it doesn't work out well and is more difficult than I thought....

I have searched for solutions on Lemma. This post made by Kasumi and her tutorial of customizing NVL textbox really help me a lot (Thanks!!), but what it achieved is "showing two NVL window styles ALTERNATELY" so it doesn't really solve my problem.

Also the former post mentioned "creating a pseudo-NVL screen" and to use it as the second messaging screen, so I tried:
1) copying the whole part about NVL in screens.rpy and pasting it in script.rpy and changing all the names (and the positions) to create a PseudoNVL screen;
2) adding a "screen="PseudoNVL"" argument when defining every Character that needs to appear at the second screen.
Upon various tests it turns out the second screen itself works well (or so I think) but is only used when I directly displace the default screen with it (and every dialogue appear only on the second screen), otherwise only the default screen will be used. The screen argument in Characters seems not to be working. I wonder if it's because I misunderstood the usage of it or something....

Meanwhile I found some posts about "how to make ADV Dialogue appear on top of NVL" (Also thanks!!), so I've also thought about rewriting the say screen (and other things related) to make it work like an NVL clone since my game does not need the ADV mode. But I don't know if it is a feasible solution and I'm afraid the whole game will go very wrong if I mess with the default settings too much.

Most of the related posts I found are about "how to change the style of NVL window back and forth" and every time you do it, you need to use an "nvl clear" statement. Also still only one NVL screen will be presented at one time.

There are plenty of dialogues and choices on each of the screen, and if possible I want them all be seen in history (or is it better to disable history and just use a viewport?), so simply presenting texts on the second screen may not be very useful for me...(as far as I know).

I haven't posted my codes here because to be honest I have little idea what I am doing. Could anyone please give me some advice on how I can possibly achieve it?
(Hopefully it doesn't include massive python statements because I'm poor in Python. But if it's necessary please tell me anyways. Or if the whole thing truly IS not practical please tell me of that as well.)

Thanks in advance!