After experimenting with various techniques such as word break and adding divs, I have discovered that Safari's behavior differs when laying out a line next to a float. It seems that Safari first looks at the left float at the top of the text line only to calculate the width of the line, which results in a conflict with the wider float at the bottom of the line.
If Safari were to draw the line where it calculated it, the text would overlap the lower float. However, during drawing, Safari places the left edge at the rightmost float on the line correctly, causing the text to extend off the right side of the screen or even start there. This same issue is observed with the use of shapeOutside as a regular box.
On the other hand, Chrome, Firefox, and Edge all display the correct calculation by taking into account the height of the floats within the line. Consequently, I can conclude that this discrepancy in text calculation within Safari may be considered a bug without any feasible design or CSS workaround. Regardless of the approach taken, if the body text intersects between two floats where the lower one is wider, the resulting line will either be too long or, in the case of a 100% width lower float, start beneath the scroll bar.
<div style="float:left; clear: left; width: 50px; height: 0.3em; background: red;"></div>
<div style="float:left; clear: both; width: 100px; height: 0.3em; background: green;"></div>
<div style="float:left; clear: left; width: 25px; height: 0.3em; background: blue;"></div>
1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9,
https://i.sstatic.net/98AY7.png
https://i.sstatic.net/0nIIt.png