I you want another side of Devotion then Harp is much easier to fit in than Scales if Sparks are not enough and you don’t feel like dumping Spirit. 8 Yellow requirement for Scales leave little room for experiments after you take mandatory damaging devos.
Dunno, I never look at the DPS thing in Grim Sheet. When playing Chillspikes you want high casting speed, conversion and that should be enough when it’s your support skill. Because you want to play RoH too as you said. And you can also use Blade Spirits or Shadow Strike. With Northerm Wyrm Chillspikes can definitely be strong which is shown by two Spellbreakers build I linked so it can be strong with Infiltrator as well.
@El_Principe You can also play DW Shooter [1.1.9.4] KAMEHAME-HA! DW Cold Infiltrator Gunslinger. (Mogdrogen, Lokarr, SR 75-76, Gladiator 150-170, Dungeons) (RoH can be included I think if you so prefer)
and Cold Flames of Ignaffar. There are many builds on YT and forum, here’s a recent one I remember: [1.1.9.0 - 1.1.9.4] Ice Unbreakable - Mageslayer Cold Flames of Ignaffar Infiltrator [sr+][mi][vid]
I forget about a recent Lolbinder Infiltrator vs. Crucible 150-170 (4:33 run) - YouTube which is RoH + AA