Both Band-in-a-Box for Windows and RealBand log a copy of the green and yellow pop-up messages to a file named "FlashMessageLog.txt". Each program has its own text file. Band-in-a-Box stores its text file at bb\Data\Logs while RealBand stores its text file at RealBand\Data.

My suggestion is for the Band-in-a-Box plugin to log a copy of the green and yellow pop-up messages it displays in a "FlashMessageLog.txt" created specific for the plugin.

Since the text file would be plugin specific a great file storage location is bb\BBPlugin\Files.
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Jim Fogle - 2020 BiaB (734) RB (Build 5) Ultra+ PAK
Cakewalk - Zoom MRS-8 recorder
Desktop: i7 Win 10 build 2004, 12GB ram 256GB SSD, 4 TB HDD
Laptop: i3 64bit Win 10 build 2004, 8GB ram 500GB HDD
Music at: http://fogle622.wix.com/fogle622-audio-home