If it is for a simple print, you can use the print settings for an outline :
(But that will print all of your custom fields. No way that I know of to choose which.)
For a compile operation, you’d have to create your compile formats (as you said) then use placeholders within them (in the suffix/prefix etc).
( → Can be done using only section layouts also.)
Or just check “metadata” in your section layout if you don’t mind all of them being in the final output :
To have exactly what you described, this is how you want your section layout to be :
plus placeholder(s) in the suffix :
And this will place your custom fields between the title and the synopsis :
→ Note that, for this third option, the title font and font size will be used for your custom metadata; as this is kind of playing a trick on the software.
Else, you’d have to use this placeholder as well :
Then you have to do it with the placeholder. My last four screenshots.
That is the only way.
(There is another way, but it would involve constantly editing each document in the editor.)