Speeding up Python Tkinter Program

Question

I have programmed an App with Tkinter on Python, that reads out a number of consecutive XML-protocols of a (literary) writing process and visualizes the same process in a Tkinter Text widget. The program is already working, a video version of the result can be watched here: https://www.youtube.com/watch?v=h3q8F8SEc68

In the video posted, I recorded a screen video and speeded up the video. Now, however, I want to be able to speed up the process on program-level. Goal is, as in the video, to synchronzie the whole process with a reading of the - naturally much shorter - product, but live, this time.

Somehow I can't seem to get the program to be running more quickly and am wondering, which is the limiting factor here. I have ruled out XML-parsing as the reason by separating parsing and visualization. In this first step the XML-files are rearranged into a list of dictionaries. An example:

chain_of_events = [...,
{'type': 'input',
'value': 'h',
'delay': 254,
'position': 648},
{'type': 'input',
'value': 'e',
'delay': 542,
'position': 649},
{'type': 'cursor',
'delay': 928,
'position': 648},
{'type': 'input',
'value': 'T',
'delay': 542,
'position': 648}, ...]

In the second step this list is processed to rearrange the writing-process. This is done mostly via a single function process(), that calls itself repeatedly. It is not practical to post all of the (messy) code here, I will instead focus on the part, that does the actual writing:

def process():
    global chain_of_events
    if chain_of_events != []:
        action = chain_of_events.pop(0)
        delay = action["delay"]
        if action["type"] == "cursor":
            if txt.tag_ranges(tk.SEL):
                txt.tag_remove(tk.SEL, tk.SEL_FIRST, tk.SEL_LAST)   #remove existing selections
            txt.mark_set("insert", "1.0 + %d chars" % (action["position"])) #set cursor position

        elif action["type"] == "delete":
            txt.delete("1.0 + %d chars" % (action["start"]), "1.0 + %d chars" % (action["end"]))  #deletion
            txt.mark_set("insert", "1.0 + %d chars" % (action["start"]))  #set cursor position
       
        elif action["type"] == "input":
            txt.insert("insert", action["value"])  #input text

        window.after(delay, process())  #rinse and repeat


# main program

window = tkinter.Tk()
txt = tkinter.Text(window)
process()

window.mainloop()