To "lock" the light simply put a piece of paper between the bat and the lamp .... If in wet conditions wax paper or plastic works
Flip the bat out a bit and pull the paper when u want to use it
heres the settings i use for climbing ... roughly 20, 8 and 2 hour duration on reactive (spot) and flood
when doing technical rock climbing flood is quite useful as it allows you to see yr footholds well ... i find that on reactive there isnt enough flood unless its on the highest setting
the lowest reactive setting is quite useful as its enough for simple approaches and last ~20 hours
as to the UI ... theres simply no easy way around it ... its something you learn or you dont
im fine with it personally, but for night climbing these days i use my 18650 fenix because of the increased runtime and output for a small weight gain .... and because the UI is so stupidly simple that i can give it to any climbing partner and theyll figure it out in a few seconds
the biggest issue with the RXP is the small buttons ... its a biatch with gloves
;)