Tried a random plugin from that site and it worked perfectly. It would be helpful to state which plugin fails and how it fails. Render to sample and render to file do work exactly identical internally, there is no way the plugin can know which of the two functions is being used, so the issue might be somewhere else.

Render to sample not work when sample frequency is other( My OpenMPT settings are 48000 hz, trying render 32000 hz sample, plugin used KX-PolyM -CSE). With other plugins, Synth1 for example, all works fine.

That's an issue some badly coded plugins have, they simply don't expect that the host might want to change the mixing frequency while plugins are loaded. Nothing that can be fixed on the host side.