The end of quarter push sounds like it's pulling people from other lines, asking people to work extra hours, etc - steps that won't be sustainable long term. They can rally the troops for short-term improvements but will need to improve their processes to maintain it long term.
That said, they will have to try to keep up and improve the pace to meet their goals for the next quarter. So even if there's a post-quarter drop in production rate, I expect it to be a short one.
I believe S/X were formerly 3 shift operations. Hit the volume, keep improving, reduce the effort.