hi, elotero.
although this discussion is very old, i want to answer your question.

make sure you have the non-steam version of this addon here.

https://github.com/MechanicalMind/melonbomber

or you can use gmad.bat to convert the file from an addon to raw form.

also make sure you have notepad++.

now, in garrysmod/addons/<melonbomber folder name>/gamemode, you should find a lua file named sv_upgrades.lua.

edit this using notepad++.

find this piece of code in the file:

function PlayerMeta:SetMaxBombs(amo)
self.MaxBombs = math.Clamp(amo or 1, 1, 9)
self:NetworkUpgrades()
end

this piece of code manages the maximum number of bombs a player can have.

in the line
self.MaxBombs = math.Clamp(amo or 1, 1, 9)
change the digit "9" to another number, like "100" in your case.
do this for SetRunningBoots, and SetBombPower.
save, and launch your own game with the melonbomber gamemode enabled.
test if this limit works.