I'd like to see if any further math could be done to isolate what the said energy/particle dump on an FTL vessel's arrival should look like, and how powerful it should be given the distance covered.
I'm curious if any observed gamma ray bursts, especially some of the more atypical "short bursts" that are often attributed to smaller burst activity relating to collisions with neutron stars etc. might actually be a venue for alternate SETI searches, such as "optical SETI", that tries something different than simple RF/Microwave SETI around the Hydrogen "water hole" etc.