L1A GC processing time

Background: I worked in USA on L1B and had 3 resources reporting to me till 2020. I was promoted to Manager in 2018. Same year I renewed my VISA for 2 more years. Everything was smooth and then COVID struck. I could not do anything but move back to my base location outside USA. After 1 year now my company is promoting me to Sr. Manager because of my contribution and has proposed to sponser my L1A VISA. I have 2 direct and 3 indirects reporting to me as of now.

I hear L1A has high rejection rate but in case I get one, I am not sure if I should be going for GC. I am in technology field and maybe would like to explore working for other companies in future at some point. I love L1 visa for the piece of mind it gives, so I don't have any intensions of H1B.

Question:
1. I am no extraordinary person, so what catagory of EB, I should most likely be applying to? 2. How long the processing might take? 3. My employer initiated L1A conversion during COVID but it did not happen that time and I had to come back. So I assume my employer already assessed my eligibility for L1A. Can I assume my profile matches L1A eligibility?

Thanks for reading!