File-Based Caching: why always split mobile/desktop?

Hi,

I’m digging into SiteGround’s caching layers to better understand their workings, with the goal of contributing ideas or improvements where possible.

I noticed the following behavior when Browser-specific Caching is disabled:

• Dynamic Caching serves a single cached version to both mobile and desktop users (which well-built responsive themes should handle correctly without needing separate cache variants!)
• File-Based Caching still generates separate cache files for desktop and mobile (e.g. index.html and index-mobile.html).

In practice, this leads to cache misses in my File-Based Caching when only one variant (usually mobile in this mobile-first world) has been generated and when a non-mobile (desktop) requests a page.

What I’m trying to understand:

1. Why is the mobile/desktop split in File-Based Caching being forced by SG Optimizer?
2. If so, what makes this different from Dynamic Caching, where serving a single version is acceptable?
3. Or is this mainly an implementation / legacy decision that could potentially be made configurable?

From an optimization perspective, it feels like there might be room for an option disabling the forced mobile/desktop split for File-Based Caching?

I’d love to understand the reasoning behind your design choice (if deliberate), and whether you see room for improvement or configurability here.

Thanks for the great plugin, and for any insight you can share!

All the best
Erik