Great you shared his tool, but might it be posible that his usage of total commander is just enough to quickly find he right files and edit them?
under linux you have commands like "find" and "grep". you can even do regex operations, so I asume this rusian guy uses equivelent total commander tools to quickly find the files he wanted to edit, made some lists of these files and then manualy edited them, copy replaced the files, packed it all and tested the game?

Looks very short, handy and why bother making a stupid GUI for if this just works?

Ow wait, till some noob will ask for your tool and wants to extract files... owman, you know me a bit, Im that dude with Linux and commandline tools. I dont think that guy ment bad for you at first. maybe the communication went downhill, but 15 euro is a bit high for something that might be easier. a donation would have been better or something. Im no expert (and I send you the link on discord) isnt this like the same file structure as: http://forum.xentax.com/viewtopic.php?f=10&t=3881 discussed here?

not sure for the windows version but under linux, " grep -rnw '.' -e 'uptime' "  lists every file that contains the text uptime (the dot means all files from current folder and deeper, replace with / for the root of the OS or "grep -rnw '/home/dimomite/porn/turok_beta/' -e 'prototype'  " will search for the word prototype in your secret prototype folders. maybe this: https://blogs.technet.microsoft.com/heyscriptingguy/2016/06/27/use-windows-powershell-to-search-for-files/
and no, not all searches posibilities can be writen to a GUI for if you need to change the search algoritm you need to recompile the tool again. I kinda like the idea of having a tool thats good in 1 thing and only 1 thing. then use excisting other tools to do the other things. (AAAAnnd,.. you can reversengineer his tool now way more easely)

Anyway, another tool to our arsenal of tools.