My advice for keeping up immolate is simple
Just watch it. Seriously. Its one dot.
I'm beginning to see why blizzard needed to prune us down. What did you guys do in the days of 5+ dots?
Sheesh.
The point of my post? Blizzard has provided a tool for us to keep dots up. It's the debuff frame below enemy portraits. Immolate appears as a small green or yellow graphic with a timer on it when you apply to a mob. When this timer is about to run out, you re-apply.
Sorry, but it's hard not to be condescending when the answers are right there in front of you.
I use Ellipsis to track my dots on multiple targets. Raven to track buffs and debuffs. But yes, tracking a single dot should be easy enough with minimal effort.
Too small, no filtering, no sorting or organising. etc.
Because some player decides the default suits them personally, it does not mean the default is perfect for everyone.
Some people use the default more to try and prove a point, because they stubbornly refuse to see that addons offer choice.
I personally find progress bars a lot easier to read overall progress on and to gauge in a hurry than I do icons with numbers.
While I certainly won't defend blizzards default UI and dot tracker as being optimal, it's certainly enough to maintain higher than 30% uptime or whatever. I know I spent an awful long time using the default UI long, long ago, and my DOT uptime was never as tragic.
You use what you have.
If that's icons from affdots or whatever, watch t hat.
If it's custom bars, watch those.
If it's the default UI, you watch that, and I'll vehemently defend it as being good enough, though addons certainly improve it a lot by offering customization that you can tailor to be clearer and have better general raid awareness instead of watching the default ones which some people might struggle with.
That aside, I definitely agree that if you're not managing with the default (and 30% uptime certainly isn't managing), then you need to find something that works. I've also been a fan of bars as opposed to icons. I used to use dottimer (or was it dottracker?) back in the day, but switched to needtoknow since then since I adore how customizable and visually appealing it is.
I will also inform you that ForteXorcist is still working - some Russian guy is keeping it updated and it still works flawless - http://www.aleaaddons.ru/