H1B conversion to L1A after 8years of stay in USA

[Jit1]

Hello Sir,

My Case is that, I have completed over 8 years in USA In my total term of 10 years since my first H1B petition is approved in 2010. I have my I 140 approved in EB2 category with priority date in 2016. I have worked with my current employer in manager role from India for 6 months last year and relocated back to USA. Currently I am in USA and planning to relocate to Canada for 6 months after which I will become eligible for L1A due to meeting 1 year international manager exp outside of USA.

1. Since I have worked for 8 years on H1B of which 5 years with current employer, would I be eligible for L1A convert from H1B after getting one year of international manager exp?

2. If I will be eligible for L1A regardless of my total years of stay in US on H1B, would I be eligible to get 7 years of stay on L1A?

3. Will this conversion to L1A anyways impacts my current I140 and the priority date, if I would attempt to port my GC to EB1c after converted to L1A status?

please clarify as this advices my next coarse of actions. Thanks.