A few weeks (months?) ago I made the tough decision to remove the Hot Spark's metal striker blade from my key chain, figuring it reduced the pocket load and that I'd find something to strike with if needed - I hope.
The only thing I use the striker that comes with the Hot Spark for is testing right after purchase (ok, actually playing around with it, but I call it testing) then I toss it aside. I always carry at least 2 other items that I've proven will produce sparks. I'd recommend sitting down with your gear and see what will work and what won't. I was somewhat surprised to find that I have an older military lensatic compass that's compatible with my Hot Spark.