The ASRc is a very capable bike. It’s happiest where most XC full susses would be terrified. It deserves a 120mm, stiff fork.
Also, once you’re talking about 2017/18 fox forks there is only about 50g (yes fifty) between the regular 32 (non stepcast) and the 34. My current 34 is 1760g. And the damping is massively improved over previous years.
Obviously a stepcast 32 would save you a fair chunk of weight over a regular 32 or 34 (still not 500, more like 350-400g) but you’d be limited to 100mm. They’re excellent forks and handle predictable, known terrain fine… but when things get out of hand I always want my 34s under me.
SIDs probably split the difference between an SC32 and a 34. Both weight wise and performance. You can definitely convert up to the 2016 (sid b) model to 120mm. But yea newer ones limted to 100.
I vote fox 34 120mm. You won’t regret it!