RE: Modifying bluetooth scan parameters via btmgmt

I have the same problem of @Hias about this topic:
https://unix.stackexchange.com/questions/420978

The more interesting answer is:
"modify bluetooth kernel module, set any discoveryFilter using Bluez (i.e.: RSSI -127)."

The answer is not clear to me.
Where is the "bluetooth kernel module"?
That is, what is the directory?

In the output of this command:

sudo btmgmt --index 1 find

Between "hci1 type 7 discovering on" and "hci1 type 7 discovering off" there is a time of 11 seconds (I counted in mind).
How to change this time?

If –timer parameter is 5 for example, i must wait other six second to execute the command, otherwise it gives me the output of busy: 5+6=11