I experienced numerous freezes during the boot of OpenSuse Leap 15.6 (kernel 6.4 or 6.14) and noticed that they occurred when loading the i915 video driver.
Many people talk about PSR and disable it by adding the following command: i915.enable_psr=0
On my Meteor Lake, this produces the opposite effect: almost systematic freezes, so I added i915.enable_psr=2 and since the phenomenon has disappeared 99% of the time.
Did you try using the Xe kernel driver with the 6.14 kernel instead of i915? i915 dates back originally to new in 2004 technology for chipsets supporting 32bit Pentium 4s. September 2020 brought a new Intel graphics technology called Xe, for which a new driver technology was introduced. Introduction of Meteor Lake (with Xe) followed over 3 years later in December 2023.
I see no date at that URL. I should think the newest kernels and newer GPUs to be farthest along in development, for which 6.14 and Meteor Lake should qualify. Once OP determines his own device ID, he could try the i915.force_probe=!#### xe.force_probe=#### method to test. Xe works in my 3 year old Rocket Lake, though when last I tested, not remotely as well as i915 worked.
You may run test glmark2 from OSS repo to check the relative performance of the two drivers. My Rocket Lake using Xe turned in only 740 when I last checked, compared to 2900 with i915. If you have similar comparability you may need to continue using i915 too, unless there’s other backport software you need, or codecs.
It may be worth booting a live TW or 16.0alpha media as a check. Indeed if you try 16.0 and get same result, a bug report is probably the best next step.