The above link is probably my best light roast attempt so far. .
I think Jim was pointing you in the right direction.
If you can keep the total roast time the same 9:15 with First crack starting at 8:00 to 8:15 you will get more of what you want.
You dont want more / longer maillard flavours and your profile is already too flat. So you will have to drop your charge temp significantly. Try the soak and at 1:30 use your max heat setting then leave it be.
You want a return to 100C around 2 mins.
Time to full yellow should be 50 to 55% depends when you call it.
Keep fan at "medium" for entire roast, you are better off not playing around with it until you get what you want in the cup.
Just after full yellow make slight adjustment to power down, this may only need to be P7 to P6 for example.
At 10C before first crack make your final adjustment and stick with it / ride it out....taste and repeat or with 1 change to that final setting.
Minimal power adjustments in a BALANCED roast profile produce the sweetest cups, especially if roasting light.