Just wanted to update this thread.
I have just done about 1500-2000 km after the gearbox oil changed (Redline Shockproof Lightweight).
There are actually quite a bit of difference now, the gear seems so much smoother than before even with colder weather morning start.
I am happy with the result so far, smooth as butter and it just slides in neatly going into 2nd, 3rd and 4th. Also able to get into first gear easier than before.
Not sure if it is killing my gearbox right now, but time will tell.
Hope this help for other seeking advice on the redline gearbox oil.
Cheers.