How can we know that this mod has no fees, and fees are not going to devs wallet?
First of all, by trusting in the humanity ! We are not all bad guy, just want to help and share something useful nothing more
Otherwise, when you launch xmr-stak.exe, it's written on the fifth line : "Configuration dev donation level is set to 0.0%"
You'll never see "Connecting to dev pool" each 100 minutes then "Switching to user pool"... Finish!
By the way, it's not really a "mod", I followed the instructions of the dev team ITSELF, downloaded their OWN files, modified their OWN file (replaced 2% by 0% as they wrote on their github https://github.com/fireice-uk/xmr-stak#default-developer-donation), then compiled everything following their OWN procedure (https://github.com/fireice-uk/xmr-stak/blob/master/doc/compile.md)... Don't know for the others, but i guarantee there is no risk with my share.