The meeting was moved from the township building to the Upper Merion Area Middle School Auditorium to accommodate the expected turnout.
The proposed Renaissance Park and Innovation Data Center campus has now entered a new, more intense phase of township review.
The five-site, 4.6 million-square-foot project spans multiple buildings and was first publicly unveiled in late May. Public opposition to the project has only grown since it was introduced.
During the meeting, one speaker asked people in attendance to stand if they were opposed to the project, prompting the vast majority of the crowd to rise to their feet.
Following public input and initial reviews by commissioners, developer Brian O'Neill returned Wednesday with revisions to three of his five applications. Some residents said the changes did not address their primary concerns.
"The plans that have been submitted are modified to include things like the sidewalk has been identified or the landscaping plan has been added, or maybe at best, a traffic impact study has been provided. But those really aren't the things that are at the top of the residents' minds when they hear about these hyper-scale data center proposals," said Courtney Smith of King of Prussia.
On Wednesday night, commissioners focused much of their discussion on zoning, power generation, engineering issues and environmental impacts.
O'Neill defended the project and pushed back against requests from commissioners, arguing they were seeking information beyond what is required at the current stage of the review process.
"I have a bunch of staff and planning commission members doing everything in their power to be politically correct in front of an audience versus give me a fair hearing," O'Neill said.
In March, Upper Merion adopted new restrictions on data center construction. However, township officials said the proposals under review were submitted before the ordinance took effect and are therefore not being considered under the new rules, which is unlikely to change.
"The plans that were submitted prior to the ordinance change are vested," Township Manager Tony Hamaday said.
However, the developer's lawyer had previously signaled they would make concessions where they deemed it was possible.
Residents continue to call for greater transparency, though some acknowledged the project is unlikely to gain their support.
"There is absolutely nothing he could say to make me amenable to multiple power plants being constructed in my own backyard," Smith said.
The planning commission is scheduled to review the remaining two applications on Aug. 12. If no additional revisions are made, the proposals could move closer to a township vote afterward.