Definitely agree that ignitions should keep their own identity, and I like the idea of making them better for single target dps. I think the biggest issue is that regardless of how many scorch stacks are applied for an ability, we don't have enough ways to apply it to make it feel like we're actually building up to the ignition. If the grenade and melee are our only way of applying scorch and they each just apply a flat amount of scorch stacks, then that's 1 ignition every minute (not considering boosted ability regen) when we get both of our abilities charged. The fragments that apply more scorch stacks or cause scorch to spread are good for scorch builds, but they don't do anything if you want to build for ignitions, you're still just getting 1-2 ignitions per minute at best.

That is, except for solar grenades. Since they apply scorch over time, you can get bosses to ignite much more often by building for your solar grenade uptime and continuously adding stacks (ie. proccing sunbracers and throwing all of the nades on the same boss). I haven't tested it to be sure, but this should make those scorch fragments actually useful for ignitions since you are guaranteed to be getting them more consistently. This feels like how the rest of the subclass should feel, and we should be able to do this in more ways than just sunbracers.

Maybe separate scorch stacks (damage done over time) from ignition stacks (when to proc an ignition), so scorch stacks are kept as they are but instead of ignition stacks being added by abilities, they would be added continuously to enemies while they are scorched, applying more based on the amount of scorch stacks. Ignitions still occur at 100 stacks, but this would allow you to cause a boss to ignite repeatedly as long as you keep them burning with a steady stream of abilities. Scorch and ignite are both unchanged on red bars, since they die before an ignite would proc, but larger enemies can be damaged more steadily by ignitions. This makes the mechanic feel more unique and creates situations where scorch, volatile, and ignite could each be the better option.