They probably should break down colonial administrations into a separate subject type, because that's where this is most frustrating: a colonial admin should not have any liberty desire and should be very loyal to its overlord.
That said, it shouldn't be a guaranteed law passage. Eg, if France tells French Senegal "stop serfdom" I think it's reasonable that they might have some trouble actually doing so given the power structures, and other puppets like French Vietnam have their own power institutions as well.
As a Japanese, when I think of puppet states and their laws, I have a strong image of the example of the puppet state of Korea(Korean Empire). In the case of Korea, it was not a colonial government but a genuine "puppet state," so let's use that example, not Belgium's.
During the Victoria III era, the Empire of Japan took away Korea's diplomatic rights and made it a "puppet state," and then imposed a number of systems on Korea.
-Abolition of peasant conscription
-Public compulsory education
-Censorship law
-Introduction of a police system
-Abolition of Korea's traditional tax system and change to a Japanese standard tax system
-Abolition of serfdom and transition to tenant farming
In introducing these laws, Japan ignored the opposition of the Korean government's IG, which included Korean aristocrats, intellectuals, clergy (Confucian scholars), and peasants. The enforcement of these laws was completely unpopular and unconsented by the local puppet government, which led to the Hague Secret Emissary Incident. However, the Empire of Japan certainly imposed all of its laws without the "consent of the puppet government's IG."
Isn't that what a puppet state's "autonomy" is supposed to be? Sovereignty is under a foreign sovereign. That's because a puppet state is a puppet.
On the other hand, the puppet state in Victoria 3 clearly has sovereignty. It says "NO" to the implementation of all laws that it doesn't like that are "proposed" by other countries. That seems "unnatural."
To be honest, I don't know anything about French Senegal or French Vietnam. I don't know what country Europeans imagine as a "puppet state," and it's possible that it's very different from Korea.
However, for me, who has the image of Korea, a puppet state that can say NO to everything seems unnatural.