Maybe Dallas didn't score one of Amazon's new headquarters, but developers, architects and economic development officials say the city gained a road map for how downtown Dallas can develop.

And, with arms wide open, they're closely watching New York City's sometimes unwelcoming reception in case Amazon changes its mind.

"We never hung up the phone with Amazon," said Mike Rosa, senior vice president of the Dallas Regional Chamber, referring to the most recent announcement of an Amazon air hub at Fort Worth Alliance Airport and a fulfillment center in West Dallas, its eighth in Dallas-Fort Worth.

Recent reports suggest the technology and retailing giant, which employs more than 11,000 people in D-FW, may be having doubts about New York City following heated political battles over incentives, union requests and displacement of residents.

"If they're readjusting their decision to place a headquarters in New York, they certainly know who to call," Rosa said, who watched all six hours of intense and sometimes hostile questioning of Amazon officials during recent New York City Council meetings.

"Wow, my goodness," he said. "Amazon was invited to choose New York. I wouldn't be surprised if they [Amazon officials] got back to their office and had a discussion" about whether to reconsider.

Rosa spoke at an Urban Land Institute panel Tuesday hosted by architects for HKS, which created a model that incorporates three downtown Dallas sites picked by Amazon when the company narrowed its choice last August to the region's largest urban core.

The model was on display during the presentation. While it presents an impressive downtown expansion conceptualized for Amazon, it's ready for other interested companies, said Dan Noble, CEO of HKS.

"Design can move the needle," Noble said. It can create density downtown, something many companies are looking for in D-FW, which now has a population spread out across a large region.

HKS was closely involved in the process of pitching to Amazon. The firm set up a "war room" for officials and developers to meet, said Linda McMahon, CEO of the Real Estate Council.

While Dallas is known for having fiercely competitive real estate developers, "everyone worked together on this one," said Todd Watson, senior vice president of Hunt Realty Investments.

Hunt Realty was a part of the downtown site that included the Reunion area, the DART train station and the former Dallas Morning News building.

The other two sites are a 20-acre area between Dallas City Hall and Interstate 30 proposed by Hoque Global and KDC and the area around the Cedars neighborhood proposed by developer Jack Matthews.

1 / 4A model of what was offered to Amazon as part of a possible Dallas HQ2 location is displayed during an Urban Land Institute panel discussion on Tuesday, February 12, 2019, at HKS in downtown Dallas. (Ashley Landis / Staff Photographer) 2 / 4Craig J. Kolstad, (second from left) Associate Principal and Senior Vice President Director of Design at HKS, shows off a model of what was offered to Amazon as part of a possible Dallas HQ2 location is displayed during an Urban Land Institute panel discussion on Tuesday, February 12, 2019, at HKS in downtown Dallas.(Ashley Landis / Staff Photographer) 3 / 4The Urban Land Institute hosts a panel discussion about Dallas' bid for Amazon HQ2 with (from left) Mike Rosa, Senior Vice President, Economic Development at the Dallas Regional Chamber; Linda McMahon, President and CEO of The Real Estate Council; Todd Watson, Senior Vice President of Hunt Realty Investments, and moderated by Christine Perez, (not pictured) editor of DCEO Magazine, on Tuesday, February 12, 2019, at HKS in downtown Dallas.(Ashley Landis / Staff Photographer) 4 / 4A model of what was offered to Amazon as part of a possible Dallas HQ2 location is displayed during an Urban Land Institute panel discussion on Tuesday, February 12, 2019 at HKS in downtown Dallas. (Ashley Landis/The Dallas Morning News)(Ashley Landis / Staff Photographer)

The unified front was noticed by Amazon officials, who made two official treks to Dallas, the first a year ago to the day on Tuesday and a second on Aug. 9.

The goal was to convey to Amazon that "Dallas has a strong sense of place and was a forward-looking community," McMahon said. "It was obvious from the start that Amazon didn't want its new home to be known as Amazon town, like Seattle is. We now absorb more than 50,000 jobs a year."

Formal presentations to Amazon didn't spend time on obvious facts such as Dallas having two strong airports, Rosa said. The group worked hard to tell Amazon what it didn't know about Dallas and to combat negative or inaccurate reports that Texas was unfriendly to the LGBT community or that Dallas didn't have a transit system, but Austin did.

So why didn't Dallas get Amazon?

Rosa repeated what Mayor Mike Rawlings has said. Amazon decided it was a talent issue.

From the time Amazon announced to the world that it was seeking an HQ2 in September 2017 to the following fall, its own expectations for growth and hiring needs advanced, Rosa said.

Those 50,000 jobs it needed over the next 10 to 15 years were "compressed into maybe half that time, and the Boston, [New York] to Washington, D.C., corridor offered more talent faster," he said.

"I'm not sure we could have done anything different," he said, adding a golf analogy. "We shot a 64 on a Sunday. Everyone here did."

Twitter: @MariaHalkias