Currently cachyos has only performance oriented kernels which are more suitable for gamers and desktop folks who dont have to worry about battery life.
It would be nice to have a kernel whose parameters and configs are set to get the maximum battery backup without hindering any functionality of the laptops.
why not use userspace programs ?
Using tlp does little help to save battery but kernel level optimizations would bring greater benefit.
The regular Arch repos serve the regular kernels plus a few more like hardened, rt, and zen.
And you have even more options in the AUR .. or you can build something yourself.
I am not sure an eco/power-saving kernel is really needed, at least from Cachy.
I found no battery efficiency oriented linux-kernel in AUR, all of the linux-zen linux-tkg linux-cachy are made for desktop gaming
While Cachy is indeed generally tweaked for performance over powersaving .. I am not very familiar with kernel builds that can optimize powersaving. There are some boot parameters and similar .. but if there are obvious build options then I am not aware of them.
I would think that the regular Arch kernel plus other configurations would be more than enough for most users.
And what avout using a powersave scheduler with scx_loader ? It’s not so far from special powersave kernel, i guess (but it’s userspace, as tlp, so maybe you do not want that)
It can run in addition with Arch wiki power settings.
On my laptop, Cachys is using so low watts in amd that, for the first time, i have to disabled powersave tweaks, assuming i do not really need 15 hours battery, so go for performance settings !