Miband 4 without Mifit

Hi,
I'm starting this topic to discuss a featrure to use Notify eithout Mifit.
I know that since miband 4 xiaomi change a way that they authorize pairing phone with band and now they've added encryption key.
But there is a way to extract this key, we just need modded mifit installed (https://yadi.sk/d/8Psmawev_9zqNg), or http://mbm.blacknote.top/com.xiaomi.hm.health.4.0.5.qexx.apk

And this modified app could extract pairing key - then we could uninstall modified mifit and use only Notify until next pairing (then we need to do this process again).
I think that a lot of people would use this, as they don't like overload of apps on theirs phone like me.

It would be superb to see it on tis app, right now I think that only "Mi Ban Master" app is using that option and because of that I'm forced to use theirs app.

Info from theirs FAQ:

1. How to use Mi Band 4 with Mi Band Master without Mi Fit?
   — Xiaomi introduced protection in Mi Band 4, which is why it cannot be used without Mi Fit, but there is a solution (by following these steps, you allow the transfer of the authorization key of Mi Band 4 from Mi Fit to Mi Band Master!):
   1) Press Settings - Exit in Mi Band Master
   2a) If Mi Band 4 is not paired to Mi Fit or paired via Mi Acc, then you can go to point 3
   2b) If Mi Band 4 is paired to Mi Fit not through Mi Acc (but through Google or something else), then you need to unpair the bracelet in Mi Fit.
   3) Unistall the current Mi Fit, if installed. Download and install the modified Mi Fi: link 1 or link 2. This modification allows to transfer an authorization key to Mi Band Master to connect Mi Band 4 without Mi Fit.
   4) Run Mi Band Master first and then Mi Fit, enter in your Mi Acc (if you don’t have one, create it, modified Mi Fit can work only with Mi Acc!), pair your Mi Band 4 in it (if it's not paired yet), wait for the firmware and resources update (if it starts).
   5) Mi Band Master should see the key (Toast will be notified on the screen), then unistall Mi Fit (you do not need to unpair the bracelet in it!). If it does not, close Mi Fit and reopen.
   6) Now Mi Band Master can work without Mi Fit, then you need to click Settings - Connect to Mi Band - Mi Band binding - Select your bracelet - Own authorization. If you unpair the bracelet in Mi Fit or pair it again, the key will change and you will need to perform all these actions again.