No, it is meant that once you take ownership of the element by applying any styles to it, you are also responsible to meet the minimum sizing requirements. You can only use this exception if you leave all styling to the browser. This is consistent with similar exceptions in other success criteria.

But I think @gundulaniemann makes a very good point, @yatil.

per the quoted text ("User agent control: The size of the target is determined by the user agent and is not modified by the author;"), I don't think it's clear at all that changing any style would undo the exception if the original sizing wasn't changed. The text is written differently than other instances where the exception is more overtly nullified if any styling changes are made.

for example, the following two SCs are much clearer that the original UA appearance/visual presentation has an exception, but if the appearance is changed, then it becomes an author responsibility.

1.4.11's language for user interface components states:

Visual information required to identify user interface components and states, except for inactive components or where the appearance of the component is determined by the user agent and not modified by the author;

1.4.13 has this exception:

Exception: The visual presentation of the additional content is controlled by the user agent and is not modified by the author.

2.5.5 and 2.5.7's exceptions are the same, and "size" is specifically called out, not any and all visual appearance as other SCs mention. Whether one agrees with whether that should be the case or not, the fact the text is different and is scoped specifically to "size", I don't think there's a strong case anyone could make based on the normative text that any style change beyond those that would impact the size would undo the exception.

agree with @scottaohara and @gundulaniemann here too, the language seems more specifically about size not being modified

@patrickhlauke @scottaohara @gundulaniemann My bad, you’re right. That said, I think the wording in the SC is sufficient to convey this.

Glad that you agree.
nevertheless I have experienced several misunderstanding, therefore I still suggest to add the word 'size' into the example to make clear that manipulating the size (or nit) is the crucial point.