I'm in this situation (bought it about 18 months ago) and have been in contact with Charles - as long as you have the original invoice he will honour the warranty. I did not get an invoice and have recently contacted Charles as one of the sockets is dodgy (you can crack it sideways and it works for an ever decreasing while, but that's not a healthy fix) his response to my question on the price of a fix and algorithm upgrade? "Tera has 2 outputs, so how about just using the 2nd output and postpone
service to when it is really needed ?" He also said I wouldn't be able to fix it but there is a video of him making it and it's a throughole part so should be an easy fix. I'm still hesitant to crack the case - wouldn't be surprised to receive a shot of pepper spray knowing Charles' sense of humor!
If you are going to but one make sure you get that invoice.