@desasteraang To disable the typewriter effect, you can change the DIALOGUE_DEFAULTDELAY constant to 0. This will effectively make all text to appear instantly (everything processed in a single tick). However, you will have to get your hands a bit dirty in the code to implement a text speed up function.
First, create a function under the "DialogueSystem" event group named to something like "Dialogue_SetSequenceCharDelay". This function should receive an optional time parameter (in milliseconds), and use this parameter to set the variable "Dialogue_SequenceCharDelay" to its value, or revert to the default value if no parameter is provided. Like this :
Next, if you want the text to "typewrite" faster when you hold the left mouse button, you could do something like this :
Let me know if I was too cryptic in my explanation.