[திங்கள் ஜனவரி 09, 2023] Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of text editors" wrote:

> Then what did you mean by:
>
>     The default value (t) implies that we change the :width image
>     property which leads to blurry images when zooming.

I should have said "leads to blurry images when zooming when using PNG
images."  My bad.  It is the same as when we use +, - to zoom in on a
PNG image in image-mode.

>>> IIUC you're saying here that when `doc-view-scale-internally` is nil we
>>> re-create the SVGs every time the users try to zoom in/out?  While not
>>> strictly a bug, it's a significant inefficiency we should address, no?
>> I suppose so.  But I'm not really sure if users out in the wild adjust
>> the variable.
>
> I set it to nil because of the blurriness.
>> If they do, then it might be worth looking into ignoring
>> that variable if we're generating SVG images.
>
> Ah, that'd be a good option, indeed.

Right, then I guess adjustment of that sort is in order.  How about the
following patch?  It should be safe enough to go to emacs-29.