Your idea is reasonable, but there are still some practical problems to be solved.

First, this foreign exchange account is only one of the reasons for excess liquidity and even inflation, not the whole reason. Therefore, it is not that Japan will not have inflation without compulsory foreign exchange settlement and sale, but that it will not lead to inflation for this reason.

Second, there is something wrong with the idea that foreign exchange earned by China enterprises should be converted into RMB abroad. First of all, it is said that RMB is not an international currency, and foreigners don't have that much RMB to complete this procedure. Secondly, for enterprises, the idea is to earn dollars (assuming dollars) and convert them into RMB, which is the same as foreign exchange settlement and sale; For foreigners, paying RMB to buy goods or services seems to be different from the settlement and sale of foreign exchange, but the premise is that RMB is bought in US dollars. In the final analysis, services are bought in US dollars, but the time is different, so it is the same for foreigners; Looking at the central bank again, it seems that your method has nothing to do with the central bank, but foreigners have already exchanged RMB for US dollars when they used US dollars to "buy" RMB, which is only a time difference. From the analysis of these three stakeholders, there is something wrong with your method.