The OP's question is important and not easy to answer.
I would think non-expert ("normal" bike owner) cannot answer this.
It would need disassembling the ECU (bin) to verify the logic for "closed loop" operation.
I have read that some (Bike)ECU have logic to detect that the O2-sensor is "tampered" with and revert to "limp mode"/restricted map. Most likely BMW
I *believe* this probably is not the case for the GSXS.
If the ECU read 14.7AFR from the PC O2-eliminator it will probably do nothing in "closed loop" operation(where the logic in the ECU executes).
*If* there are some logic in other running conditions that takes the AFR as input, then this "idiot sensor bypass device" is a bad solution.
But as Mythic posts above if the OEM O2-sensor is not a quick reacting Wideband sensor then the input is not used for calculating fueling (although I do not think *any* modern engine, even for bikes, uses a "pure" narrow band sensor these days).
Narrow band sensors are also only fairly accurate from a tad over stoich (14.7) to the lean side.
On the rich side it is way off.
It is a matter of mapping the whole area, but only for the TPS/rpm map, using PC.
When we know that this map is different depending on which gear is used and that there are maps also for IAP in the ECU, the use of PC is sort of a good compromise.
Personally these days I think a good remap on the OEM ECU done by a skilled tuner will give just as much (or even more) that using a PC/Bazzazz device.
But this takes more time and needs access to ECU.
This is why PC/Bazzazz and similar are good products to accomplish whatever desired for your bike to a much lower cost.