|The "construct" you are referring to is called the heredoc syntax.|
The heredox syntax behaves exactly like text that is delimited with double quotes. It will evaluate a PHP variable in the string, but it will not perform any operations on it. The only difference/benefit of using the heredoc method as opposed to double quotes is that if the text includes double quotes you do not need to escape them with a backslash.
Personally, I try to always separate my logic (the PHP code) from the presentation (HTML/CSS) as much as possible. So, I typically have very specific HTML being generated in my logic. So, I don't use the heredoc method.
For example, if I need to present the sum of two values, then I would do the logic (the adding) in the PHP logic and save the value to a variable. Then in the HTML I would include the variable.
It may seem easier/quicker to just put ($a + $b) inline with the HTML, but you lose flexibility with your code.