“Then, the U.S. government would issue them dollars, which the C/J/B would attempt to exchange for RMN/yen/pounds”

JG, only FED has authority to print or issue dollars, not the US govt. The FED buys US treasuries and pays for those paper receipts or treasuries by dollars it has in its stash or that it has printed. This is how dollars are added to the system and the concept of “inflating” the economy with more money comes from this. When FED liquidates these bond receipts, it returns the paper receipts and asks US govt to return the dollars it had borrowed from FED. US govt does so by raising taxes, cutting spending, etc and hence takes money out of the system and thus the concept of deflation. The last method is rarely used as FED instead uses borrowing rates to control monetary policy.