I failed to really mention that is a bad idea ... I thought about using the space for a tool kit or something, but even thats a terrible idea. Its just too hot.
It is always nice to have the starter though. I kick my bike 100% of the time, but I have needed the E-start when its cold because I literally ran out of energy to kick.
My bike struggles to start when its below 50*F/10*C and I can imagine that you would still be riding in those temps where you live. All of my old bikes are much harder to start when its cold, except the K100 but only because its fuel injected. The battery I use is just enough to get the engine cranking and youll have about 15-20 seconds of E-start power before the battery is drained. Points ignitions will work with a battery drained to as little as 10v, probably less, but an electronic ignition will not fire below say 11.5v
When its a few degrees above freezing youll be glad to have the E-start lol. Its saved me a couple times.
If you want to shed as much weight as you can, its the first thing Id remove. Riding the bikes I own, the XS is plenty lightweight the way it is. The sportster literally feels like Im sitting on a steam train.