OK… here goes. Assuming you followed the installation instructions correctly…
If you open the file at…
\Mega_Bezel_Packs\Duimon-Mega-Bezel\zzz_global_params\Graphics\user.params```
And edit the contents from…
// DUIMON MEGA BEZEL GRAPHICS AND PRESETS | https://duimon.github.io/Gallery-Guides/ | [email protected]
// SOME RIGHTS RESERVED - RELEASED UNDER CC BY NC ND LICENSE https://creativecommons.org/licenses/by-nc-nd/4.0/deed
// ----------------------------------------------------------------------------------------------------------------
// GLOBAL GRAPHGICS :: BEZEL
// Custom Parameters specific to the [Bezel] presets.
// ----------------------------------------------------------------------------------------------------------------
//#reference "/params/batocera.params"
//#reference "/params/batocera_nocurve.params"
//#reference "/params/batocera_hud.params"
to this…
// DUIMON MEGA BEZEL GRAPHICS AND PRESETS | https://duimon.github.io/Gallery-Guides/ | [email protected]
// SOME RIGHTS RESERVED - RELEASED UNDER CC BY NC ND LICENSE https://creativecommons.org/licenses/by-nc-nd/4.0/deed
// ----------------------------------------------------------------------------------------------------------------
// GLOBAL GRAPHGICS :: BEZEL
// Custom Parameters specific to the [Bezel] presets.
// ----------------------------------------------------------------------------------------------------------------
//#reference "/params/batocera.params"
#reference "/params/batocera_nocurve.params"
//#reference "/params/batocera_hud.params"
(Remove the two forward slashes from the second from the last line. i.e. “uncomment” them.)
All of my “[Bezel]” presets will now look like this.
This is a custom bezel configuration that I developed for my Batocera decorations contribution.
If that works for you then we are done.
If you insist on the game screen meeting the top and bottom edges the non-integer scale needs to be changed to 100. (This is hard to do in the parameters dialog, but you can get close, save a simple preset, and edit the value for accuracy in a text editor.
That will give you this.
My biggest issue with the result is that the bezel covers up some of the background graphic that I intended to be seen.
My “CRT” presets (And most others.) all adapt to ultra-wide aspects automagically. This means that increasing the background “X Scale” parameter will nudge the two sides further apart to give you this.
This won’t guarantee that essential elements aren’t covered, but you stand a good chance.
Saving a simple preset with all of these changes yields a preset with these contents. (I also changed the “Bezel Inner Edge Thickness” to account for what may be a bug in either the shader or my presets.)
#reference "Mega_Bezel_Packs/Duimon-Mega-Bezel/Presets/Standard/SONY_Playstation/Playstation-[STD]-[Guest]-[Bezel].slangp"
HSM_NON_INTEGER_SCALE = "100.000000"
HSM_BZL_INNER_CORNER_RADIUS_SCALE = "80.000000"
HSM_BZL_INNER_EDGE_THICKNESS = "60.000000"
HSM_BZL_OUTER_CORNER_RADIUS_SCALE = "60.000000"
HSM_BG_SCALE_X = "103.000000"
Delete the top reference line to get this.
HSM_NON_INTEGER_SCALE = "100.000000"
HSM_BZL_INNER_CORNER_RADIUS_SCALE = "80.000000"
HSM_BZL_INNER_EDGE_THICKNESS = "60.000000"
HSM_BZL_OUTER_CORNER_RADIUS_SCALE = "60.000000"
HSM_BG_SCALE_X = "103.000000"
Then rename the file to “full.params” and place it in the folder at…
Mega_Bezel_Packs\Duimon-Mega-Bezel\zzz_global_params\Graphics\params
Then edit the aforementioned “user.params” to this…
// DUIMON MEGA BEZEL GRAPHICS AND PRESETS | https://duimon.github.io/Gallery-Guides/ | [email protected]
// SOME RIGHTS RESERVED - RELEASED UNDER CC BY NC ND LICENSE https://creativecommons.org/licenses/by-nc-nd/4.0/deed
// ----------------------------------------------------------------------------------------------------------------
// GLOBAL GRAPHGICS :: BEZEL
// Custom Parameters specific to the [Bezel] presets.
// ----------------------------------------------------------------------------------------------------------------
//#reference "/params/batocera.params"
#reference "/params/batocera_nocurve.params"
//#reference "/params/batocera_hud.params"
#reference "/params/full.params"
All of my “[Bezel]” presets will now share these parameters. 
Making global changes to my presets was among the motivations driving the development of my “Boilerplate”. This solution illustrates the inherent power of my methods. 
