Thanks ! I have been saying that for years.
They said it was going to be added next year to playback the generated tracks to the DAW tempo changes from within the plug-in, I don't know if that meant December release or mid 2021 ???
You can generate it with ACID info (in Preferences) meaning when you drag it into the DAW it will fit to the tempo map of the DAW if it supports ACID, or some will let you set the bpm of the file then fit it to the Tempo map. Pro Tools will do this, but the plug-in won't play the track back in sync to the DAW from within the plug-in until you drag it into the DAW.
Another feature that should be added some time is being able to drag a midi into the plug-in from the DAW that has the tempo map, the plug-in will then set the tempo changes in the plug-in also, thus it will render the the track already tempo mapped.
The thing is as you say the SGU format only stores whole numbers and not decimal points for the tempo map so if it could allow that or have another save format like RealBand that has decimal point tempos.