Okay, I just got off the phone with another agent whose name and PID I collected. I asked him of my eligibility to apply on Implied status for PGWP and if I am able to work when I do that.
The answer he gave me about Implied status application did not sound too convincing - although I didn't need him to convince me since it is on their website - he sort of rambled on about how processing times are not correct and I might have to apply for PGWP on implied status and hope the officer reasons along those lines when processing the application.
On whether we can work if we applied for PGWP on implies status for study permit, he consulted with some "consultant" on the background and returned by saying unequivocally that "NO, YOU CANNOT WORK unless your study permit was active at the time of PGWP application".
My conclusion from the conversation is that the whole thing is up in the air, at least until the IRCC updates their website with specific instruction for that scenario.