Can one limit to part of a JSON file

I have the current version of FNC Maps and am using OpenLayers to show several hundred point symbols plus a JSON polygon layer. The polygon layer contains several thousand (up to 6000) polygons but this is very slow and I do not need to show all the polygons. In most cases I could work with 1 to 3 polygons. Is there a way to limit the number of JSON record loaded (filtering for example).

I do everything inside Begin/End updates commands and have tried to identify specific polygons with known JSON values in one of the fields but none of what I have tried works.

Any suggestions would be appreciated

Adding a high number of polygons to the map can indeed cause slowdowns.
However it is unclear exactly how you are adding these polygons.
Can you please provide a test project or sample code so I can further investigate this?