I just looked up your pre-purchase question, but there is no mention there of connecting the existing content layout with the filters. I though you meant searching and filtering users, as you wrote in your email.
It's not really the plugins issue, this is simply not possible with any plugin out there, you will need a custom coded solution to be integrated with the existing content. That could be very costly, in my opinion.
Replacing that content with the search results shortcode I think it's the fastest and most reliable solution for this, and it's all built in to this plugin as well, and it won't cost you anything. The isotopic layout is even very close to what you have right now on the page.
There is also an auto populate feature available, if you want to display some results initially. That would achieve almost exactly what you needed.
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