Nice to hear it is working better now.
I think the delay between down and up was/is the key!

Thanks for reporting back.
It was late and I sleeepy
Fixed it and putting it as 0.5.4 to devel.

About currentSIM:
it is working flawlessly for me and mine (others adapters?) do need it, so I am going to keep it in (not making it configurable). As the new 'sim-switcher reactivate' almost is the same as activating the current active SIM.
Your switching code is '002' for second SIM and '001' for first SIM, right? Please check your config files for SIM1 and SIM2 again.
Using the op name may not be unique (SIMs from same network).
But please test it again and give me more details, so we may overcome that little beast also
And push it further to testing.