Is there a way to make a custom askopenfilenames dialog window or at least edit its title bar, close button, etc in tkinter?

Question

I'm making an app in tkinter which uses the ttk.Scale widget to show the process of an mp3 song. I have a function that I want to add buttons with the names of which (the buttons) should be relied on filenames. Therefore I've made this example:

from tkinter import Tk, Button
from tkinter.filedialog import askopenfilenames
from tkinter.ttk import Scale
from threading import Timer

root = Tk()

slider = Scale(root, from_=0, to=100, orient='horizontal')
slider.pack()

# slider is continuously set to a bigger number so that it keeps going
def update_slider(num):
    slider.set(num)
    num += 1
    root.after(50, update_slider, num)


update_slider(num=0)

# this function creates buttons based on the files opened 
def add_buttons():
    # the 'X' button of this particular window slows down execution of update_slider function
    files = askopenfilenames(title='Add Buttons')
    for i in list(files):
        Button(root, text=i).pack()


button = Button(root, text='Browse', command=lambda: Timer(0.1, add_buttons).start())
button.pack()

root.mainloop()

The problem I'm facing is that when I open the askopenfilenames dialog box or when I press its 'X' button, my slider which is running continuously in the background gets stuck, and as a result doesn't show the process correctly.

Here is a picture where I hold down the 'X' button and the ttk.Scale stops moving:

I've tried using threading to run the add_buttons function but the behavior of the program remains the same.

Can I edit the askopenfilenames dialog box with something similar like overrideredirect(True) so that I can make my own title bar and 'X' button and the events generated not to slow down my Scale?

Replying to:

I cannot reproduce the issue in Linux, the scale keeps moving no matter what I do with the filedialog window. So this may be an OS specific issue.

I'm aware that this problem doesn't appear on Linux. I faced the same problem with the root's close button and other Toplevels' close button, but I fixed it by replacing the title bar using overrideredirect(True).
Is there anything similar I can do with this askopenfilenames window?