Hey Johannes,
"AProVE was not using _Fixed?" Yes, we sadly didn't have the time to optimize our new DPs for relative SRSs as they were mainly invented for relative TRSs, but we still wanted to show that they can be used for SRSs as well. We still need to implement Matrix interpretations for them, etc.
The "_Fixed" version is simply the strategy from last year. This is also the reason why our certified version is better than the version without certificates.
Next time, we plan on having a more refined strategy for relative SRSs again!
Best, Jan-Christoph