So I haven't worked on Bedrock in a very long time (or this pack in a while either lol) but taking a glance at the bedrock assets, it seems like you wouldn't be able to port it one to one. In my version, the textures were changed and then the models were changed to fix the issue of the chiseled and cut variants using the same texture files, but it doesn't seem like there are sections for either the slabs, or the chiseled or cut variants in blocks.json bedrock file (the textures exist, but it seems like the models are hardcoded for some reason lol but i could be wrong about that and just missed something)

However, I think there's another way to achieve the same outcome. If you went and changed the models for the standard red sandstone and stairs, that might also affect the slabs and hopefully also not have an effect on the chiseled and cut variants? I'm not too sure how that would go but it might be worth a shot!

If I can help some more just let me know :)

Go for it! :)