Hello there!
Sleheyron Story mode is out on here and on NexusMods. You can already play it if you install it manually.
About compatibility :
Placeables are indeed an issue. However, for Sao's Sleheyron Story mode, it is actually a relatively small one, as it doesn't add half of what was added by BOSSR. Which means it could theoretically even be completely compatible with K1R. At any rate, this shouldn't cause any incompatibility with neither K1CP nor RC-K1CP.
However, the main issue is patching existing modules, 2da files, dialog.tlk and global.jrl. Idk how much you know about KOTOR modding, but these files are very annoying : either you replace them, or you patch them (meaning adding new files and modifying others for modules, and adding/modifying rows in the tlk/jrl/2da, all of that inside the said files) with TSLPatcher or HoloPatcher (more modern and efficient so this mod will use the second one). Setting up the Patcher thus takes some time, which is why he said some additional work will be needed in the future.
FYI, I am currently working on setting up Holopatcher to help players install the mod. This does not mean that I'll fix every compatibility issue right now, but that you'll be able to install the mod with the Patcher, for Sleheyron Story mode 1.1. As it is already out, we might make Holopatcher patch everything. I'll see with Sao about it. Anyway, more compatibility will be added in the relatively near future.