I wonder if there is going to be an issue with the structural integrity of the filters, since they are designed to rest on an object rather than hang? Wouldn't think it would be a big issue, but possibly? If you were wanting to do this long term, feels like a series of light wood frames to support would not be too expensive/difficult to construct or possibly 3d print, and have advantage of reduced adhesive smell.
Most filters (especially the 1" and thicker ones) are surprisingly sturdy across most dimensions except for torsion.
Thinking about 3D printing, you could probably print a nice corner bit, that would hold the corner of 3 filters together and square to each other. That would make the whole assembly easier to put together and seal up with tape.
As long as the filters are adequately supported at the edges it shouldn't be a problem. I know because my house has two 12x24 HVAC filters which are only supported at the edges and are almost certainly subject to much higher rates of airflow.
