Newbie - being switched to Strive

Hello newbie here — I signed up and paid for my first dose on 4/19 and my order was sent to Empower on 4/22. After not receiving any updates on shipping for ~13 business days, I reached out to Emerge to have my order switched to a different pharmacy. As of 5/9 they have switched me to Strive Pharmacy (Tirz + b12 + glycine). I’ve read some posts on injected b12 causing some acne which worries me, so looking for some info:

1. For anyone receiving their meds from Strive, what has your experience been, and have you had any unexpected side effects?

2. How is Emerge customer service if/when you communicated negative side effects?

3. I asked Emerge if it’d be possible to switch back to Empower in the case I had a negative reaction to the Strive compound and they told me they’d only be able to fill my script through Strive — has anyone been able to switch pharmacies more than once?