Modding for me used to be getting power and performance out out of the car, then I would sell it before the build would start to decay and start over. This is the first time I have kept my modded project this long and now I am having to cope with wear issues. The trans is not failing so I can stop here and just enjoy but when you are a compulsive mod freak then you pretty much have to go forward. Of course this will mean built motor and bigger turbo if I beef up the trans..... logic right.
Last year on April I bought the SSP 500hp clutches kit and I faced lots of problems to install it due to many factors (the old basket model I had, slipping after installation, not smooth shifting, etc...).
There were Jerk & Shakiness in the 1st, 2nd and Reverse gears. It happened between 1000 to 2500 RPM and it was noticeable and you can't ignore it.
It looks like you are using a damaged disk and clutches in a manual transmission!
I communicated the support and I followed all what they mentioned, recommended and advised but the issues were always existed.
I pulled out the gearbox more than 7 or 8 times and kept trying to let it work without any success.
So, to end the story I removed the SSP clutches and installed another OEM basket and car is working fine now .. Thanks GOD!