Hello Konstantinos, I pride myself in providing excellent support, as most customers can confirm. In your case, I replied to your email from Jan 31 on the same day. Please check your spam folder. Most customers will also try the Tindie forums before leaving a negative review. I respond promptly to both.
Without the drivers installed, the base behavior of the addon board is a little weird -- literally no way to turn off the pi without the drivers installed. Additionally, the mechanical support of the addon board is very poor. It feels like the control board might easily break, and there's limited support for the battery enclosure to be anchored to the pi. Overall, though, it gets the job done, given you provide some form of additional mechanical support for the addon around the pi it's attached to (ie: the LiFePO4 Pi case).