Need Opinions. Have nothing to compare to.

A wideband can show the impact of changes. Its a handy tool, but not a neccessary tool. Tune to the performance. Check the spark plugs for the best view of what was going on inside.

That said, I would't bother with buying a sensor like that. A oxygen sensor needs a controller and interpretor to give AFR. AFR gages and loggers work with specific types of wide bands. This is true even within a brand. My older LM1 uses a different WBO2 than the newer LM2.

Its nice to have extra parts, second engine, etc. I hope you continue tuning with your current set up as well.

As far as the missing data, it may not be entirely gone. If they still have the *.drf file, those datapoints may be there as mph vs Hp. It just may not show on Torque and RPM. On a dynojet, RPM is based on the inductive pickup and the torque is caluculated based on assumed or entered gear ratio. OTH maybe its not important - water under the bridge.