I need advice to avoid this screw up.

I just finished sanding a R&Q S&B R.O. floor.

I sanded the field and edges with 36, 50, and 80. I then sanded the edger marks out with a palm sander with 80. I normally use 120 g for the final screen, but I didn't have any. So, I buffed with 150 g screen.
I applied the stain with a wipe on/off and immediately saw that I picture framed the floor.
I realize now that I should have used a lower grit screen, and that would have helped the walls blend with the floor better, but I have the feeling that I am doing something else wrong.
Details:
I run the edger using a thin (1/16"-1/8") white pad, but I still seem to get edger scratches so I then use the palm sander with 80 g as well.
I buff counter clockwise then clockwise. I start in the middle and work my way to one wall and then go back to center, flip my screen and start the other way.
Do I need a new edger?
Does anyone know of the multidisc? Would this be the solution?

I ended up being able to blend most of the stain difference by buffing the field with very fine maroon pads. This lightened the transition.

All suggestion are appreciated.

Its pretty simple really, you broke the two grit rule when you jumped 100 and 120 to 150, youre only supposed to skip one grit max.

Personally on a job youre describing I would have gone 36, 60, 100 drum and then buff at 120. Even when I hit my floor with the 3ds I still have to palm the edges and check carefully. Its the nature of the beast. Charge accordingly.

I think as you transition from drum/edger to buffer you shouldnt skip a grit to make sure you have a deep enough scratch to remove the previous one.

As mentioned , you might have jumped too far ahead on the screening.A multidisc has some advantages as it can blend the edges to the field more quickly. I have one and it's pretty good but it also has a tendency to take big slivers out of the floor which requires repair. So it isn't a cure all type of machine.Also, most guys using the multidisc still leave a heavy scratch pattern in the floor . Many guys use 80 grit on the multidisc which in my opnion is way too rough. I use 3M regalite 120 grit on mine and it still leaves enough of a scratch pattern that i have to use a 120 grit screen afterwards.

Thanks guys!

After posting my question, I began reading some of the other posts and realized the error of my ways.
I ordered a multidisc today and plan on using it as a step prior to buffing.