Is there a topic limit?
I am wondering on that as well, because of the spaces in the topic menu.
I think there is no topic limit. You will always be able to scroll down for how long you want, although is getting very confusing and hard to find if you have very much topics. I think we don’t have to worry about a limit for topic, but more about the incompatibility with mods because of topics. How more topics, how more incompatibility problems. That’s why the Expansion Pack Mod isn’t really adding topics anymore. 
I am missing my like 30 custom topics
wow @KageCoder, try the research all topics option in @kristof1104 cheat mod, to see if they appear.
I did they are not there
what other mods do you have active.
my mod and cheat mod that is all
then, there’s something wrong with your code. PM me your code and I will try to find what is wrong with it
ok i will