Actually, the track archives are the oldest - as far as I remember, they were already available as a feature in Cubase SX2 - and not able to save reliably the routing whenever a VSTi is used in an instrument rack slot (multi channels/outputs configuration). Same thing for the track presets : they appeared with the VST3 standard (Cubase 4) and are as useless as the track archives, in this case.
Added to this, the Import track from project… command has the same issue : if, for a VSTi set as an instrument rack , we select all the tracks involved (MIDI and VST Instruments folder, including its content), only the MIDI tracks will be imported : the corresponding VST instrument folder stays empty.
At the end, Cubase still don’t allow us to make reliable track templates (including the routing). This, in the 2021 year, and seeing that Reaper (2 developers…) allows this without issue… Workaround ? Carefully make as much project templates as needed : it’s the only reliable way to make things working as expected in Cubase. 