Thanks to everyone who responded.

I believe I found a workable (for now) answer that doesn't take too much time. It's still a work in progress to nail down exactly what I want, but I thought I'd post my possible solution in case anyone is interested in doing the same thing. If anyone tries this method, I'd appreciate it if you could let me know if you find an easier, better, alternate or additional option way.

I modified the Style Picker Category > Show All Categories listing to show the categories that I want by doing the following:

Close BIAB
Goto [your drive] BB\Data\ and find stylz_kategories_MENU.txt file and make a copy just in case.......
Open the stylz_kategories_MENU.txt file and remove the categories and names that you want to exclude in the Style Picker All Categories list. Apparently the category names are in the dashed lines and the categories are listed underneath, like this:

------------------------------ COUNTRY STYLES ------------------------------
EVERYTHING COUNTRY$Country
Country Ballad$Country Ballad
Country Classic$Country Classic
Country Contemporary$Country Contemporary
$$ More...
------------------------------ MORE COUNTRY STYLES ------------------------------
Boom Chick$Boom Chick
Rockabilly$Rockabilly
Spaghetti Western$Spaghetti Western
Country Swing$Country Swing
Country Waltz$Country Waltz
$$end
------------------------------ TRADITIONAL/WORLD STYLES ------------------------------
Bluegrass$Bluegrass
Celtic$Celtic
Folk$Folk
World$World
$$ More...
------------------------------ BLUEGRASS ------------------------------
Bluegrass Waltz$Bluegrass Waltz

Save the file with the exact same file name stylz_kategories_MENU.txt
Restart BIAB.
In the StylePicker under Options > Set StylePicker Options, uncheck the box on the setting of "Default display should include all styles (available and N/A not available)"

On my installation of 2026 the only main categories listed were now the ones that I saved in the .txt file. I did not do a rebuild, and I'm holding off on that until I'm sure that everything will be working ok so far.

I'm going to do some fine tuning as time allows by changing some other things in that file and perhaps one or more of the other .txt files in that BB\Data area, but this is the starting point for me.

***Please make a copy of any files that you change before you begin and proceed with caution, as I don't know yet how these changes affect anything else in the program or workflow. YMMV

Best regards to all
BluegrassPicker