A firstrib version of that would be identical in size but provide all the usual KL functionality (assuming the tiny KL utility scripts were added). But FirstRib (with some KL utilities) produced a commandline (non-GUI) Ubuntu FossaFocal distro that was also 78 or 79MB in iso size, and could be expanded to offer Wayland/Sway or xorg-minimal as a medium sized (couple of hundred MB) distro.
I've played with 4MDistro in the past (the full GUI version). It is really like Puppy and very nice to use. In fact it was included as a FirstRibIt script option, which results in a 4MDistro with full FR overlayfs functionality (up to 99 sfs compressed or uncompressed normal directory addons) and full KL capability if the tiny KL utility scripts were added. The most important feature to me would be the package management in terms of dependency resolution and expandibiliy - so the ubuntu-based wee FR-fossafocal was very useful (and was how, as a FR build-script spin-off, I first provided Puppy Linux itself with an apt/dpkg addon prior to much the same being incorporated by others into official Debian-based Pups). The only person I know who used that original apt/dpkg Pup addon was rockedge though (and myself of course in experimentation).
bakandimgcd sounds interesting, but depends on its package management; tiny tiny size seems irrelevant nowadays (except as you say if really wanting a limited specific functionality) - a few hundred MB is already tiny if using any computer from last ten years, but making tinier ones (like tinycorelinux) is an interesting hobby experiment that helps us keep bigger offerings more efficienctly tuned size-wise too. Overall I'd tend to just use 4MDistro itself though, but I can't remember if that provided persistence out-of-the-box nor what package management (repo size and so on) was like for it (turns out provides no package manager - so that was the drawback). 4MLinux could certainy be considered a Puppy competitor overall though. https://en.wikipedia.org/wiki/4MLinux
