Coordinating a equipment ban between allies against China will likely be limited in success. Because sure, banning may disrupt the semiconductor industry in China, but this will spur the incentives and investment into developing a domestic alternative, which is worse for US and their allies in the long run. Its better to continue selling equipment to stifle the growth of a domestic alternative and gain more leverage by having the industry be depended on foreign equipment.
Preventing sales of Chinese equipment manufacturers from selling outside of China is a better idea, it will stifle their growth even further combined with the previous strategy. But China's objective should be mainly self-sufficiency, and development of leading edge ones second. I suggest China to pro-actively support the industry through subsidies and collaboration between semiconductor industries, ban imports for foreign equipment when a domestic one is available and production is enough to meet domestic needs, in order to give them more and maintain the current market share, which will help the sustainability and development of their company.
Once China reaches a certain level of self-sufficiency and US still belligerently pursue their strategy of decoupling, they can do the nuclear option of completely unrecognizing patents related to semiconductors from foreign countries that worked with US on the decoupling strategy, because a lot of semiconductor research currently in China is just finding another way to do the same thing. Though this is a major escalation on its own, so I don't think will China do such a thing, unless they want to or have already completely break from the West.
