The former BMW M engineer and senior executive tells us that while we can expect routine enhancements along the way for the GT cars we already know - and maybe some new ones - the company is not working away at any significant 'step up' models like a V8-powered Stinger or a 2.0-litre, 200kW Cerato GT+.
"At this time, there's no plan [for a V8]. We have the Stinger GT, and the GT label is for the sportier Kia cars, like Cee'd GT and Optima GT, and the V6 in the Stinger," Biermann says, promising the GT badge is the pinnacle for Kia sports models.
"I think there's no need. I think with the Stinger GT, we are entering an area we have never been before, and I think we should go step-by-step.
The company isn't planning any other enhancement items for the Stinger, either. Think BMW M Sport, with its add-on aerodynamics and styling options.
"The aftersales business, that is done mostly by our local markets. So Australia might think about doing some dealer options… I know in Germany they have the 72, 73 decibel sound limitations - we cannot deliver a car exceeding that limitation, so immediately they started to make an aftersales exhaust system. Australia as well," he says.
Biermann again poured water on the idea of a new performance sub-brand for Kia, along the lines of the N division he heads up for sister brand Hyundai.
"For Kia we have the GT, and that's good enough. It's not its own division, but we don't need that with Kia. Our mission for Kia is 'The Power to Surprise'," he says, invoking the successful slogan that has played a part in the Korean brand's continued growth.
"Hyundai is a more serious, quiet brand… we couldn't do something with Hyundai [alone], so for luxury we made Genesis and for the crazy guys we made the N brand, you know?"
"Anything is possible for Kia at any time."
Anything, it seems, except a properly mean hot hatch. Of course, that doesn't mean Biermann isn't keen. He's a performance engineer, after all.
"I'm ready any time to do one more step up. From an engineering point of view, that's not the issue. The substance is there, with the Kia cars - we could go one step up at any time if we would decide so," Biermann assures us, but baby-steps is the course for now.
"The establishment of the GT cars, that is already strong stuff, to bring it out into the marketplace. Once that GT step has been done successfully and established well, maybe then, between the GT customers, there might be guys who want to go one step up. When that time comes, we'll be ready - from an R&D side - to take that step."
Don't expect Kia to take a cue from BMW or Mercedes, though, offering a proper GT variant of just about every model in its range.
"I don't think so. We will not make a GT on every Kia model. I mean, [a Sportage GT] is probably a nice idea, but it's not in the roadmap.
Asked if Kia would ever consider a rival to something like the new Ford Edge ST, Biermann said: "Of course, why would we exclude it [from consideration]? You can always make a sportier car of everything, but is there a market there for that?"
We say there is, but that's why we're journos and not product planners for a brand that's shown it already has some idea of how to get ahead.