It would be very helpful if JMC could open the GC log files and present a graphical representation of the GC log files.
There is an existing GC log visualization tool - GCHisto:
There is no active development on this tool. It should be looked at if we can revive this tool and tie it into JMC.
There is a GCLog Plotting tool developed and maintained by JVM performance group:
It is worth looking if this tool can be integrated with JMC.