Travel Zoom - Do I need one?

I used to own an LX100, loved its travel convenience but not its image quality and have since switched to an LX100 II as my secondary cam. The difference in IQ is marked and I now love the LX100 II for both its excellent travel form factor and pretty darned good IQ. There's definitely some HUGE pluses for the LX in terms of being able to tuck it into any coat pocket (or tossed into any little bag for that matter) that will be a godsend in the myriad of situations that travel brings. In Europe specifically, there were many instances in museums and galleries where they did not allow my bigger cameras and had to store them in lockers but when I flashed the LX, they nodded and let me in! It's also much easier on my conscience to bring it out at crowded, cramped restaurants and bars without it feeling like an intrusion to my family, other patrons, or the owners of the establishments. No matter how good my other cameras get in future, I have a feeling I will always travel with the LX as part of my gear for this very reason.

I don't have an X-E3 but recently purchased an X-T2 and I don't think I would bring it absolutely everywhere when traveling, no matter what lens I have on it.

As for low light, indoors and night capability, there are two things to consider:

Lens-wise, I think once you work out the equivalence, you might be surprised how well the LX fares. According to this site: https://mmcalc.com/ you will find that the LX's f/1.4-f/2.8 is better than the two zooms you have picked for the X-E3.

Sensor-wise, the X-E3 wins, no doubt about it.