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Unless your going to make it work for T-Mod yourself, It isn't going to work with T-Mod as it wasn't made for it
which is what i though you were trying...
T-Mod isn't a requirement, and isn't listed as such nor in the readme
However People requested the previous version for 1.3.5 (so it's the oppesite way around)
as T-mod apparently makes 1.4 run as 1.3.5 or does it convert 1.4 back into 1.3.5?, no idea
and thous i don't know how to help you with such...
I would suggest you try and talk to someone more in the know about the current version of T-Mod
Making it for "Texture pack" feature on the other hand, is another thing
But that requires everything loads and isn't ignored...
like the Player character was in the "Experimental" Textureapack feature back in Terraria 1.3.4
and a few other things....
but that is something i will look into later, when i have made everything planned so far
or probably beginning with "wave 3" hmmm....
as I'm Fairly sure the Add-ons would had worked, doing the "Beta" for the Texturepacks Feature