Question CPU Overhead with Hybrid Renderer V2 and Subscenes

I Have a 2D game with lots of High Definition Sprites, most of them are used to add depth and detail to the foreground and background.

I made a branch of my project to start experimenting with subscenes as a tool for world streaming and content management.

I Installed Hybrid Renderer 0.5.0-preview 6, and Entities 0.10.0-preview 6. I set up Hybrid Render V2 as well.

After that I packed up around 100 sprites, which were just simple prefabs with transforms and sprite renderers, and packed them into a subscene.

When I run the game the render thread is the same as before at 0.2ms, but my cpu main is now 1.5ms up from 0.4ms.

I'm wondering what might be causing this spike. I'm familiar with ECS, but relatively new to DOTS and data oriented design when it comes to optimization, so if there's something fundamental I'm missing here I'd appreciate some pointers to good resources.