[Google Pixel 4a 5G ROMs, Kernels, Recoveries, & Ot] bubbyj:
Here's my brief experience:

Let me preface this by saying that I didn't installed the Proton OS.... only the proton kernel. I used the latest version (1.2). Its snappy and offers a noticeable improvement over the stock kernel. My 5 run antutu baseline increased by 8,200 points. GeekBench increased by almost 100 points, again using a 5 run average to smooth out outlier results. However, my battery life was the worst I've ever experienced in 10 years of android. When I went into ExKernel Manager to tweak the parameters to encourage decreased battery consumption. It was then that I saw that minimum freq was set at 1363, with no option to go lower.

Overnight standby had a drawdown of 16%, with no data transmission. Daytime moderate-heavy use was drawing down at a rate of more than 18% per hour. Again, I don't know if it was because the proton kernel wasn't being fully utlized by the proton OS (as the OP suggests). I was running the stock android 11 -- rooted w/ Magisk. And its stripped down big time. My running services at any given moment number between 6-8. I run a very very lean environment, as a personal preference.

Camera use was especially devastating. I would get an overheating warning within 10 minutes, and the CPU's would throttle down to the point that the camera was practically unuseable. And considering that photography accounts for about 1/3rd of my entire day... it was frustrating.

I also had charging issues with this kernel. (I'm not entirely sure how that correlates, or if it even does). I have a 25w charger and can pull 4500+ mah with it on Ampere, on average. Especailly for the first 50% of charging. However, with this kernel installed, I was only able to hit 1920mah. And it hit it like a brick wall. It stayed exactly at that rate. (While with the stock kernel, usually the charging rate fluctuates by 100mah +/- every few seconds or so.) In addition to this, sometimes the charging rate would limit to 960mah (exactly half the max rate).

And I've read through several of the reviews on here... and see none that resemble my experience. This leads me to believe that I have a conflict somewhere on my phone.

I have viper4android, edxposed, LP (don't judge), sytemless host and EP ultimate, custom Gcam, ExKernel Manager. But not much else, other than a few regular run of the mill user apps.

As a test though, I did a format and fresh reinstall using the latest image from Google Image's library. Then put the kernel in, and this didn't seem to help after a few hours of use.

I'm not running the ExKernel 1.07, and with my heavily tweaked paremeters, my 9 hour standby drawdown is less than 2% (1.7% to be exact). My one hour SOT with moderate use is less than 10% for the first 50% of the battery. My total SOT is 9 hours. Over 2.25x as long as with this kernel.

I would very much be interested in using the Proton Kernel again, and this message is meant to say nothing about its use, nor should it be seen as a recommendation to not use it. However, this is a very accurate description of my experience with it. Can anyone here, especailly the Developer, guide me on what to look for to correct the battery issue and overheating (with camera use)?

Thanks so much for all your hard work, and being one of the few and true devs for this device. It doesn't go unappreciated.