First, has the trial finished, second is there a recommended supplier of systems
First, I don’t think it’s even started yet, second, no.
If I join the trial, will I be able to find out how much I export but be able to switch back to deemed export if I’m worse off? And will I keep getting my generation tariff the whole time?
Octopus have a better FAQ available.
IIRC, once you’ve opted out of deemed export you’ve opted out*.
You may not need to opt out of deemed export for Bulb’s alpha trial, I believe they were setting it up as a test and so were not actually buying your energy…just paying you as if they were.
Yes, your generation tariff is unaffected.