Directive on text input with mask: separator.0 + leadZero=true changes numeric form control type to string

[LoadedWithHay]

🐞 bug report

Is this a regression?

No

Description

When using mask directive with expression: separtor.N (for example: separator.0) with flag [leadZero]=true and using Angular Reactive Forms, a form control is changing it's type from number to string.
It's caused by the method _toNumber: It checks if it's a SEPARATOR expression and if leadZero is truthy.
Why is that? I think the form control type shouldn't be changed via mask. Especially by the SEPARATOR expression mask which should be always a number?
Is this a desired behaviour?

My problem is that if a user is typing for example 23 in an input, the control.valueChanges output is "23" string, but should be a number.

this.control.valueChanges.subscribe(console.log) // <--- displays "23" string instead of 23 number

🔬 Minimal Reproduction

<input
    mask="separator.0"
    [leadZero]="true"
    formControlName="myNumericFormControl"
/>

🌍 Your Environment

Angular Version:

latest