If you have BBW4 creating the data instructions files you should be able to get it to create all the frozen SGU tracks and instantly and import without the need to generate up.
If I open it in normal BBW the tracks show instantly so it should work the same way with BBW4 and instantly write the track data to the SavedTracks for BBPlugin to read and write to tracks (the time it took me to type this sentence out it could of done it 100 times).

The data files should be able to be dropped into a track, this way you can revert back anytime to another generation, so they are not lost.
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Any frozen SGU's should be instant with ALL the tracks with the same sections:

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https://stash.reaper.fm/u/ReaTrak (Scripts for Biab Reaper)
Open SGU in Reaper Instantly