When Did Chop Marking Coins In China Finally Come To An End?

I have a fair interest in Chinese chop marked coins, and I was wondering if there are any known records of when chop marks finally came to an end in China? I've read a few online forum discussions where people mention 1933-1935 being the official years for when chop marks ended. I believe this has to do with an edict made by the Kuomintang where they demonetized many of the silver coins in circulation in China during then (I could be wrong on the specifics of the law passed). However, China is a huge place and given how weak the central government was at the time, I wouldn't find it hard to believe that some regions of the country still continued to chop silver crowns. Of course, a lot of the coins we see today with chops are predominantly older pieces from the 19th century, such as the Spanish 8 reales pieces and US Trade dollars. I don't see too many "Fat Man" dollars heavily chop marked and I've never encountered a memento dollar with chop marks. Perhaps there was no need to chop these coins specifically because of their relative modernity and backing by the government at the time? Given the chaos China was experiencing then as well, perhaps the velocity with which these coins circulated was far less than older pieces, including the 8 reales during the Qing dynasty (prior to the revolution of 1911).

The reason I ask is because chop marked coins have become very popular and collectible today, yet many of us do not really know much about them, the origins of each stamp, the history of the practice (especially in the 20th century), and the meaning behind each character. Many people today (my apologies for generalizing) seem to simply collect them because of the mysteriousness and ambiguity that's commonly attributed to the "orient" during that time period. There just doesn't seem to be much readily available information out there for any collector interested in learning about these stamps.

For example, I often ask myself why chopmarks tend to come in two different sizes, with smaller marks most commonly being found on 8 reales pieces, and larger marks commonly found on US Trade dollars. Are there any chops out there that are considered very valuable, perhaps in markets in China? Can marks be classified by who was behind the chop, what region in China they were most likely made in, and if these marks can be classified into different eras of circulation?

I'm just throwing some of these questions out there as food for thought. I'd love to read any responses from more seasoned collectors who may have more knowledge on the subject. As a younger collector, it's often frustrating to see that most articles online on chop marks focus on their market value, and not so much the history. The online numismatic material readily available on the subject currently is quite small given the amount of searches available online today.