1.) Because SP10R will be a (slightly) improved SP10S using another LED. Sofirn is still in development of a driver capable of running Andúril and providing dual chemistry support (1.2-1.5V / 3.2-3.7V). Andúril cannot be used on lights using 1.2-1.5V batteries yet. Eventually, SP10R could be delayed.
2.) For reasons of costs as developing another AA/14500 driver running with Andúril would allocate a lot of Sofirn‘s resources and may have an impact on SP10R‘s sales price.
3.) As much as I like Andúril, for now the UI of SP10R is meant to be kept very simple to reach a broad customer base buying a small (deep red) keychain light. That’s why we also decided to refrain from using any strobe modes in SP10R.