Right, but even a phased array will give you sidelobes, it's only a question about reducing them, right? Your claim that there are no sidelobes at all seems a bit dubious to me.
Or is there some metamaterial "magic" going on even at the transmitter that I'm not accounting for?
Right, and anybody who knows enough to ask you about sidelobes likely also knows enough to know that too.
That's why, if you reply that "there are no sidelobes" you're only harming your own credibility.
A good reply is something like "there are sidelobes, but they peak at -{believable number} dB and are contained to within {small area}. We believe this is more than sufficient to address sidelobe concerns because of {standards}".
"I'm not disclosing basic performance metrics because you might reverse engineer my secret sauce from the basic performance metrics"? Really? Seems unlikely.