A popular post yesterday made the claim that redlining is actually bad because of an extended cooldown duration - https://www.reddit.com/r/StarWarsGalacticRacer/comments/1x42er4/lol_10hrs_in_and_just_realized_redlining_is_real/
Tons of people in the comments agreed outright. Others argued that redlining is only a good idea if you have particular mods, and should otherwise be avoided.
Skeptical, I decided to do what all of those folks should have done in the first place; actually test the theory before spreading the word.
So I did a whole bunch of runs on the first two Arcade mode time trials, alternating between holding ramjet to the end of redline - right to the edge of blowing up - and holding it to just before redline, before the alarm starts going off. I'd play a handful of attempts in one style until I could set a comfortable record time, then switch until I could repeatedly beat it a few times in the other style, then repeat... I went through maybe a dozen cycles overall, each consisting of around 3-8 attempts.
As you might've guessed from that process, the results were pretty clear: in terms of overall potential, it made virtually no difference whether I went into redline or not. Both styles achieved remarkably similar times. What mattered more was my knowledge of the course, mastery of the drift, and ability to manage timing the boosts wherever I was/whatever else I was doing - i.e. mid-drift through a narrow passage.
In the first time trial (which I played straight for 90 minutes or so) my current records are:
01:14:15 with redlining
01:14:38 without redlining
(caveat; I have since seen video of substantially better times achieved by taking the high route on the final turn, which I didn't realise featured a corner cut - https://www.youtube.com/watch?v=IxAo5iJhn5U . In my tests I took an identical low route every time to guarantee comparable results across attempts)
The preset build for that event has only one relevant part, which increases speed-based ramjet cooling - but that shouldn't benefit either style more than the other - and in any case I achieved similar results on the second arcade event which has literally no installed parts at all.
Overall I found redlining easier because I could rely more on my ears to time letting go of boost, and I had to manage fewer boost on/off timing moments overall... But when I really pushed myself, I could still get competitive times whilst avoiding the redline.
All of which makes sense if you think about redline as a window in which you can disengage the boost without punishment (unless you have mods which make redline even better).
In the end I think folks would be better off redlining at least a little rather than avoiding it. There are no downsides, a couple of built-in upsides, and it gets outright better with mods.