It doesn’t vary by client much, there’s a baseline of expectations that what you deliver can be further worked on by anyone using the software that 95% of the industry is using.

Dammit, I’m familiar with using kbuntu desktop at work for years and am wanting to try Linux at home, but it’s sad to hear I’d have a steeper learning curve

It’s more about ingesting their house design guide in proprietary formats. But you will also be contractually obliged to deliver back working files along with the final deliverables, and they will specify formats and versions.