Tier 2 (General) switches to BNO visa

I am a Tier 2 (General) holder with visa valid until 2022 and would be able to apply for ILR by then. As we are originally from Hong Kong and holding British National Overseas (BNO) passports. Unfortunately, I have recently got dismissed and it means I have to find another sponsorship for the remaining 1 year of Tier 2 visa or apply for BNO Visa.

From most of the cases, it seems the approval time is by luck and some are more than 12 weeks or even leads to 6 months. Great help from manci in this forum that it is confirmed that while waiting BNO visa approval, I couldn't work for any new employer unless they could sponsor Tier 2.

May I ask the following if possible please:-

1. From what I understand, during the process of switching Tier 2 to BNO visa, the old Tier 2 should be revoked and convert to BNO visa. In case while waiting for BNO visa approval, if there is a new employer could sponsor a new Tier 2, should I apply for new Tier 2 and withdraw from bno visa? Would this has any impact on the 5 years ILR router? As suppose the old tier 2 is combined with bno visa and if now i withdraw bno visa application and apply for new tier 2

Literally like (i.e. Old Tier 2 -> BNO visa ->New Tier 2)

2. The time while waiting for BNO visa approval, would it be counted for the 5 years ILR or not?

I am struggling on should I keep finding a new Tier 2 sponsor within 60 days before my employer notify HO about termination. OR just apply for BNO visa and wait for approval? Any advice or recommends would be helpful.

Many thanks!!!!!