Issue was caused by buffer shadows were binding buffer after offscreen buffers was bind which lead to some unpredictable results. Made it so ED_view3d_draw_offscreen wouldn't bind any buffers and for proper shadows ED_view3d_draw_offscreen_init should be manually be called before drawing to an offscreen. This should also make open gl render with AA enabled a bit faster. Also fixed missing sequencer cache invalidation when open gl render type is changing. Material and Rendered modes are still a TODO for sequencer.