When loading a track, especially one with a virtual instrument, a lot of time is spent loading the plugin, and a lot of RAM can be used as well if it is a sampler-based instrument which has to load a lot of samples.
This prevents us from using a trick that many professionals use in Cubase etc, which is to have a lot of tracks but for most of them to be disabled, and only enabled later when needed. The song loads quickly and only loads samples needed for active instruments.
Ideally, the plugin would not be loaded until the track is enabled, and it would be unloaded when the track is disabled. This could perhaps use the same underlying system as "Transform to Rendered Audio" in terms of preserving the plugin state while it is unloaded, and restoring that state when it gets loaded. The difference is that no audio needs rendering on disable or removing on enable.
With the absence of track templates, a feature like this is even more important, because otherwise there's no easy way to drag in your favourite instrument/preset/effects combinations to the tracks you work on. You either have to create these in several separate pseudo-template songs and then remember which is which so you can Import Song Data, or you need to save presets and FX chains and remember which ones go with which and re-create them afresh each time.