The tailswitch in this case acts as a lockout. When I carry the light in a bag/pocket, I turn it off on the tailswitch to avoid accidental e-switch activiation. However, as soon as I get a chance, I'll be updating the firmware/MCU to a ATtiny25 with my new firmware that supports an e-switch and power switch functionality. You can fully operate it on the tail switch with NOINIT, memory, etc., but also the e-switch is fully working like my standard e-switch firmware - Best of Both. I think the LD-1/LD-2 drivers work this way as well.
This X6R is perfect for this ATtiny25 upgrade (see https://budgetlightforum.com/t/-/34900). I needed more code space to get the combined e-switch and Star_NOINIT working - think it took 1070 bytes currently, where a 13A is limited to 1024 bytes. Also want to get the 25's temp sensor iimplemented, but didn't start on that yet. The ATtiny25's I have are a simple drop-in replacement for a 13A, but the 45's and 85's are a wider footprint, and require either to clip the pins or bend them to fit on a typical 13A driver board. Wight's 22mm FET+1 driver though can mount a 45 or 85 direct without bending pins.