Upgrade iPhone to current iOS minor release versus going to the new major release version? When updating my iPhone from settings the only option is iOS 13.X, however I am currently on 12.4.1 and want to simply go to the still current patch version 12.4.3 which came out just a few days ago.

Is there a way to make the phone go to the minor build update instead of forcing to 13.X? I want to avoid iOS 13 until a couple of fixes come out that address the major issues plaguing that update, but don't want to have current security holes in my current version.

There was a similar question here: Upgrade iPad to newer (but not latest) iOS but it had to do with a middle jump to an already revoked older version i.e going from 6 to 7, when 8 was the current version, so my question is different in that both versions are currently signed by apple.
Good question. My guess is that you can do it if:


you use iTunes 
Apple is signing an '.ipsw' file for your iPhone model.


If I was trying to do this, I would look at https://ipsw.me/product/iPhone.

They seem to have a good / easy system for figuring out what is available for which iPhone.

Update:

If you have a 6s, it does not look like that model is supported. At least that is what I gather from looking at https://ipsw.me/12.4.3.

Update 2:

https://iosindex.com/iphone also reminded me that there are at least two versions of the iPhone 6s, the "GSM" version and the "everyone else" version. Their pages for each are linked below:


iPhone 6s (GSM)
iPhone 6s (Global)