Will B35AM be an upgrade over something like 519A in stainless S7?

I have S7 with nichia 519A in 3500K and 5A buck driver. I love the design of S7 and want to buy it in stonewash version and i was thinking about pairing it with B35AM in 2700K but i have some questions
1. How is sustained output with stainless host and B35Am with boost driver? With my 519A flashlight is not getting super hot only at 10% and below. Maybe someone is using B35Am and can answer this
2. From my understanding buck driver keeps the output the same until battery voltage goes below forward voltage of emmiter but boost driver should keep output the same until battery is dead?
3. Is Convoy boost driver more efficient than buck or the diffrence is so small i wouldn't notice?
4. Does anyone know max lumen output in 6v 2amp drier with b35am? I only found review for s2+ and its 700 lumen only. This will be the same with stainless host like S7?
5. Can Simon swap pill and reflector if i ask him in the note at the end of purchase? S7 is awalible with B35AM so it will come with deep reflector and shallow pill but i would like it with thick pill and shallow reflector from S2+ because i want to try out diffrent tir lenses from S2+. If no i would propably buy s2+ to swap guts in between hosts.

Thanks in advance.