This is a bug that’s been reported a few times here, and has been plaguing Cascade for years - any curve that uses the emitter time (instead of particle lifetime) as the X axis doesn’t read values after X=1 second. So as a user, I have no ability to animate things like initial velocity/size/color/alpha, emission rate, location offset, etc past one second.
I’ve recently had an engineer look into this, and he was able to correct it quickly, so I’m hoping we can pass this fix back up to epic.
I think you are just not understanding how curves work.
0 = begin of particle.
1 = end of particle.
problem solved.
that said, it would be nice to have an option to switch between “0-1 space” and “over time”.
As a vfx artist, I never ever had issues with it, not even the ones mentioned in the two links you provided.
I suspect you’re not understanding the difference between emitter time and particle lifetime. What you described is particle age normalized (aka lifetime). However, the modules I described actually use emitter time (i.e. time since the emitter turned on), so you can do things such as change the spawn rate over the duration of the effect (obviously you don’t want to control the rate of particles spawned over the age of one particle?), or even the animation of the initial location of the effect. These types of controls are crucial to making an interesting effect and as a fellow VFX artist, they’re badly missed 
I run into this every semester when teaching my students, and have to explain that this is a silly lingering issue in Unreal. So no, definitely not problem solved.
In that case, make sure emitter duration (in required module) is identical (or longer) than the length of those curves.
that should solve it.
Yes, it should, but it doesn’t… which is the entire reason for this post…
I was a little dumb founded that you aren’t seeing this issue, and I couldn’t tell if it’s because you weren’t bothering to check, or because it’s since been fixed. I grabbed an install of 4.13.1 and tested it there again - it is working correctly in 4.13.1, but not earlier versions (4.10.4).
So great - problem solved!
that is really odd, as I was dumb founded you did have that issue hehe 
TBH never bothered to check the situation in 4.10, and been using 4.12 since its release. (4.13 has some other bugs with cascade)