They, in the past at least, have been a sloppy fit on the SSQA and have required shimming at the lower pin slots.
I bought four SSQA attachment plates from them a fews years back, along with the "roll-your-own" parts to build the tractor side SSQA.
As per usual, it has taken me some time to get around to completing all the projects (build tractor side SSQA, convert regular bucket to SSQA, convert pallet forks to SSQA, build SSQA shrub bucket, build SSQA root rake/grapple)
In some cases if this is not done the attachment escapes the pin on one side and will damage the SSQA if not caught pretty quick - that is before any backdrag type of force is applied with the implement.
I discovered the issue when I got the root rake/grapple completed and went to use it.
On several occasions, I've had one side of the grapple come detached ... with damage to the tractor SSQA.
On closer investigation, there appears to be a significant gap (>1/4" - 3/8") on the left side on at least
two of my plates (regular bucket and root rake/grapple)
I have not examined the other two ... but I suspect that there will be a similar defect on those as well.
Also, on the parts for the "roll-your-own" tractor side SSQA, the tubes - or at least one of them (right side) - that the retaining pins slide in, are too short ... allowing the pin(s) to cock themselves in a mis-alignment when trying to lock them in ... necessitating reaching down with my other hand and futzing around with the pin to allow it to slide in.
Hopefully they have instituted better quality control measures at this point.