Modpack: All the Mods 9 - To the Sky - Version 1.1.5
Forge Version: 47.3.33
Minecraft Version 1.20.1
Cable-Facades Mod Version: 1.2.3

So I added this mod to the All the Mods 9 pack so that I could hide my cables better, but prior to doing this, I wanted to see if a lot of facades would cause lag in my base so I started doing some tests in a creative world and found that facades start to lag your game very quickly.

All of my tests used the Mekanism Universal Cables but I also did some testing with the Pipez Universal Pipes and had similar results. I only took screenshots for the Mekanism Universal Cable tests I did. My normal FPS is 144.

So what I did to test was place a bunch of the universal cables down and putting facades randomly on the cables which resulted in my fps going down to around 45-50 consistantly:

I then thought that maybe it was because of how the universal cables were rendering sometimes in front of "solid blocks"(facades) and some weren't, so I did a test where I placed the same number of universal cables down and surrounded it with normal blocks and destroyed a bunch of the normal blocks in a random pattern to emulate how I placed the facades down in the previous test. There were no facades placed below:

When this didn't cause any lag I thought that maybe it was the universal cables causing the lag in some way, so I placed a bunch of the cable down and it caused no lag:

Finally, I wanted to see how many facades I had to place until my fps dropped below 100 and I found that it's only 256 of them(or exactly 1 layer of a chunk).
https://github.com/user-attachments/assets/eaf78e79-7cca-4fe3-a833-42e81da3a2d7

I should also mention that my fps is a more stable 120 - 130 fps when I'm simply not moving and just looking in the direction of the facades.

For the tests above I used the following settings (everything not shown is the default settings):

Additionally, the facades seem to potentially be ignoring the player's render distance settings when deciding whether the facades should be rendered or not. When the player is at a high render distance and they x number of chunks away from the facades and then set their render distance to x - 2 number of chunks and keep flying away, the player can still see the facades for some additional chunks when they shouldn't be able to see any. For example, you can be at a 32 chunk render distance and fly 4 chunks away, then set your render distance to 2, and you will be able to still see the facades for another few chunks away, then they will start to un-render. Also, if you were to go within the actual chunk distance that you're rendering and leave it again, the facades will actually properly un-render at your render distance. Here's a video demonstrating this:
https://github.com/user-attachments/assets/61b81132-fe4d-447d-a48e-341c90ba3342
What I did in this video was:
Have 32 chunk render distance -> fly to 4 chunks away -> set render distance to 2 chunks -> fly further away while still being able to see facades -> fly towards facades until I'm in the 2nd chunk -> fly away 1 chunk -> can't see facades.

Have 32 chunk render distance -> fly to 5 chunks away -> set render distance to 3 chunks -> fly further away while still being able to see facades -> fly towards facades until I'm in the 4th chunk -> fly away 1 chunk -> can't see facades.

indeed that's a very concerning issue. thanks for the report. that issue has been fixed in 1.21.1 because neoforge added the possibility to put the facades directly into the chunk's geometry but today i tried to do that in 1.20.1 but couldn't. I hope i'll be able to fix the issue but i don't think i'll succeed.