Slight correction to my initial statement above - upon searching I see that Grim Damage does in fact exist and is several years old. It is made by @slipperypete, the author of Item Assistant.
If I was ever aware that he made this I apparently forgot about it.
http://grimdawn.dreamcrash.org/damage/
He notes it is deprecated due to lack of interest but claims it is still fully functional on his nexus page for the tool. Have you at least tried it out to see if still works? If it does then it could easily be a better solution for you than Grim Internals.
Since it’s a 3rd party tool that operates outside the game it really shouldn’t matter at all if it was compiled as x86(32-bit). x64 systems and operating systems can easily run both 32-bit and x64 programs so this shouldn’t be any kind of an issue for you.