Entering song select has seen a hit since the new renderer
implementations. The underlying cause is large numbers of vertex buffer
uploads (the counter hits >200k for me during the transition).
Song select is in the process of being redesigned, and we are probably
going to make improvements to the renderer to alleviate this, but in the
mean time we can greatly improve the user experience by reducing how
long the initial fade in delays take on panels.
Visually this doesn't look too jarring, and gives a more immediate
feeling when scrolling. It's also more feasible to load elements sooner
with https://github.com/ppy/osu/pull/23809 applied.