Max, rather than guess at the cause, I suggest you pull up the latest panic log and find out exactly why the phone is rebooting. I still maintain that SMC/True Tone verification isn't a thing, at least not something that would cause a boot loop.
Go to the Kernel Panics wiki page and use that to locate your panic logs.
iPhone Kernel Panics - iFixit
Screenshot or copy & paste the first page of your log, then come back and edit your question to add that information.
Adding images to an existing question - iFixit Repair Guide
Once we have more information based on your log, we can point you in the right direction on how to fix your phone.
By the way, I'd like to clarify your meaning when you use the term LCD. For a very long time, all phones were made with LCD displays, so people have gotten used to calling the display an LCD - even when it's not. Most newer, higher end phones including iPhones are using OLED displays these days, but there are still plenty of phones using actual LCDs.
In the post you referred to, the OP actually replaced his OLED screen with an aftermarket LCD display, so they were correct in calling it an LCD because it was. There are many of those available, as they are far cheaper to manufacture than OLED displays, but the display is going to be both thicker and require more power due to the need to add a backlight, which OLED displays don't require.
Anyway, I would like to ask if you really mean an actual LCD display, or if you're just calling an OLED replacement screen an LCD?
Okay, your panic log is showing error code 0x100000. There's another wiki page regarding the SMC Panic Assertion Failed kernel panic here.
iPhone SMC Panic Assertion Failed - iFixit
According to the information, here's what your code means.
iPhone Model: iPhone 15 and 15 Plus
Sensor Array: 0x100000
Likely Issue: Front Sensor Assembly *
*Replacing the front sensor assembly will disable True Tone and auto brightness functionality, even when using an original Apple screen. Face ID is also disabled, unless the iPhone is running iOS 15.2 or newer.
So yes, if the new screen didn't come with the Ambient Light Sensor/Proximity sensor front sensor assembly and you didn't transfer it from your old screen, then yes, this is exactly the error you're going to get, and it will keep boot looping to infinity and beyond until you install or replace that assembly.
138 
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