@yetanotherid
Thank you for your patience and dedication.
In fact, now I see the confusion I was making myself. I am trying to normalize the volume of a very large music library and I would like everything to reflect the most modern standards in this regard (LUFS/LU).
Studying various articles about it, now I realize that the first collaborations from you and @j7n , in fact, have already solved my needs. The problem is that I made some mistakes with all these terminologies and ended up creating confusion here, I apologize sincerely.
I am a fan of ReplayGain and its original specifications. The current rules from EBU R128 and the like, left me lost, but there is no other way: you have to get used to them because it is the language of the world today.
Resuming, I place below the syntaxes that perfectly provided my needs (all credits go to @yetanotherid and @j7n ):
LUFS:
$if(%replaygain_album_gain%,$puts(X,$sub(-1800,$replace(%replaygain_album_gain%,.,)))$ifequal($get(X),0,0,$ifgreater($get(X),0,$replace(+$substr($num($get(X),4),1,2),+0,+),$replace($substr($num($get(X),5),1,3),-0,-))).$substr($num($get(X),5),4,5) LUFS))
or
$if(%__replaygain_album_gain%,<$puts(temp,$num($sub($replace(%__replaygain_album_gain%,.,,+,),-21800),5))$ifgreater($get(temp),20000,<->,<+>$puts(temp,$num($replace($sub($get(temp),20000),-,),5)))$num($substr($get(temp),2,3),1)<.$substr($get(temp),4,4)< lufs)
LU:
$if(%replaygain_album_gain%,$puts(X,$sub(500,$replace(%replaygain_album_gain%,.,)))$ifequal($get(X),0,0,$ifgreater($get(X),0,$replace($substr($num($get(X),4),1,2),+0,+),$replace($substr($num($get(X),5),1,3),-0,-))).$substr($num($get(X),5),4,5)LU))
or
$if(%__replaygain_album_gain%,<$puts(temp,$num($sub($replace(%__replaygain_album_gain%,.,,+,),-19500),5))$ifgreater($get(temp),20000,<->,$puts(temp,$num($replace($sub($get(temp),20000),-,),5)))$num($substr($get(temp),2,3),1)<.$substr($get(temp),4,4)< lu)
Both styles give me the result I wanted, just in a (interesting) different way.
As far as Track Gain is concerned, I only replace %replaygain_album_gain% to % replaygain_track_gain%, and my boat does float perfectly, as you mentioned at the beginning.
Thank you, again, and please excuse me for any misfortune... I'm trying to adapt (even if it's a little late) to the new specifications...