Rainer, about this quote (in bold) "I don't know how difficult it is to integrate the electronics (transistors), but according to Suresh Venkatesan it is just "engineering, it is not innovation, it just takes time, and that’s what we’re working on. But I’m confident we’ll be able to get there, whether it’s going to be exactly in June or a few weeks here or there. I don’t see any challenges other than being focused 100 percent."

I believe this was in reference to the "integrated VCSELs and detectors in the second quarter", not the "full-fledge transceiver" which "the plan is for the end of the year".

My understanding is that the timeline for the VCSEL, detector, and electronics is end of year, and June(ish) was the VCSEL and detector (optimized).

I may be misreading what you wrote, which started out with "how difficult it is to integrate the electronics (transistors)", but I think Suresh was not talking about that when mentioning "engineering".

Good luck!!