For force bolt, I will be completely honest and admit I had not considered making it a line attack during my initial planning, and I like the idea you've presented here.
In that case, is it possible to cause the activation of one power to near simultaneously activate a second power by the same caster at the same $Target?
To sidestep around the Arcanatime problem of needing to animate two attacks in a row ... could the first power activated have what amounts to "no activation time at all" (making it animation invisible) and then letting the second power activated "carry the animation time" for the combination? That way, you would essentially be "automatically chaining" two attacks together, giving you slightly different yields for each of the two components.
Attack 1 = 0s animation
Attack 2 = full animation duration of original
That way, you get what amounts to "simulcasting" of the two attacks at the same $Target from the original caster.
Where stuff will just go completely bonkers doing that though would be in the tooltips and powers performance details reporting, if the tooltips are showing only half the info (because two different powers activated as one click).
I know that City of Heroes was originally designed as a "execute ONE AT A TIME" game engine, so this may not be possible. However, not being familiar with the spaghetti coding underneath the hood, I do have to wonder if there's a way to finesse a solution. If there isn't then "oh well" ... it would simply be "back to the drawing board" of using a 5º Cone attack that then spawns PBAoEs of Knockback splash around $Targets (1 splash radius per $Target!) that get hit by the Force Bolt. Perhaps less "elegant" of a solution than the cone within a cone approach, but ultimately if it's Stupid But Works ... was it really all that stupid?
If you do try a 5º Cone that spawns PBAoE Knockback splashes around $Targets (because the Cone In Cone option is not available as a solution), then I would recommend a Max Targets: 5 on the 5º Cone along with a Max Targets: 5 for each PBAoE Knockback splash radius spawned around $Targets that get hit. Such a combination would yield a theoretical maximum of 5x5=25 KB splash hits, although that cap will almost never be reached in actual gameplay (the positioning of Foes will almost NEVER be that favorable).
Alternatively, if you want to get REALLY creative ... you could do a 5º Cone that spawns CHAINING Knockback splashes (ala some Electric attacks and Ion Judgements) that "jump" a short distance from the $Target(s) hit by the 5º Cone out to hit nearby Foes with the Knockback splash. A narrow line cone for damage that uses short distance chains to do knockback splash could be VERY INTERESTING in actual gameplay, since the chains would not be a predetermined shape (spherical) ... meaning that in
Target Rich Environments (such as Team-8 and League play) the Knockback splash wouldn't be entirely pre-determined and predictable. Instead, the Knockback splash would "fork outwards" from the 5º Cone of affected $Target(s) and create a sort of "bowling alley" FEEL to how the power works (sometimes you get a Strike, sometimes you pick up the Spare, and sometimes you wind up with Bedposts). Using short range chaining for the Knockback splash would give Force Bolt an extremely unique "character" to how the power works in combat, sufficiently so that it wouldn't feel like a gimmick but more like a natural consequence of how the power ought to "behave" (visually) when used.
Just some more
Ebil Ideas™ for you to have fun with, if you're so inclined.
