FORGE MOD
This mod allows you to gain saturation past the default maximum of 20.
If you don't understand, here's an example: If you have 19 saturation, and you eat food that gives you 4 saturation, you will now have 23 saturation. However, eating food again while already past the maximum will not exceed the maximum any further unless you set canGainPastSaturation to true in the config file.
Config - SaturationOverflow.cfg
canGainPastSaturation=[true/false] - False by default, allows you to gain extra saturation even after you have overflowed it.
This mod goes well with food mods like Pam's HarvestCraft where some high tier foods may exceed the maximum saturation to begin with, especially when using something like ScalingHealth where wasting saturation like that can get annoying.
This mod should work in both client play and server play and hopefully not conflict with anything.
This mod is open source, you're free to use the source for your own things or fork it if I give up on it. Although it's pretty simple.
This mod is free to be packed into modpacks.