Microsoft Defender that comes with Win 10 -- Good enough by itself?

Meeker Morgan said:

Quick scan.

It will Quick scan even if you do not tell it to.
I also have mine set to scan at a time of my choosing [daily, 10:15, when I'm not likely to be doing anything intensive] and I think that satisfies Defender so that it never feels to need to initiate a Quick scan of its own when I'm busy with something.
I never notice any slowing down of other work during Quick scans. Perhaps I would if I was doing something intensive at the time.

I've set up a Full scan task as well but that only runs when I want it to. Full scans are designed to root out remnants after a malware attack has been cleaned up by Defender. There is no benefit in running Full scans at any other time.
This used to be stated quite explicitly in the relevant MS article but is not in its latest version.

MS said:

A full scan can be useful on endpoints that have encountered a malware threat to identify if there are any inactive components that require a more thorough clean-up.

Now they just say

Because of the time and resources involved in a full scan, in general, we don't recommend scheduling full scans

Quick scan versus full scan and custom scan - MSLearn

Meeker Morgan said:

It's already updating automatically.

Yes. Windows update takes care of that. I have inhibited Windows update by setting my networks as 'metered' so I also have to run a task to achieve this.
Defender updates [well, I should say Windows security updates, I suppose] include both updates of the platform itself [Defender, Windows security] and updates of the malware definitions it uses.


All the best,
Denis

Meeker Morgan said:

Interesting. What triggers Defender to do the quick scan?

Some unknown, undocumented process within Defender.

Denis