Problem was having too many concurrent workers opened at once. Garbage collection apparently works very slowly on workers. Solution was to close them manually, after model data is sent to main thread.
Also some progress with Blender scene exporter. Some scenes now export correctly, though monkey test scene got worse, even with less hacky code.
Changed materials a bit to look better with lighter environment map.
Added space to buttons HTML so that Firefox don't draw them sticked together.
Also re-added htaccess for BIN files.
alteredq
Mr.doob