Christian Plätzinger we will only backport critical bugfixes to 5.3.

But... the good news is that 5.4 is really the direct continuation of 5.3 with only bugfixes (except if you use EntityGraphs where there are a few improvements) so upgrading to 5.4 should be easy.

I plan to release 5.4.0 next week, you can already check CR2 works for you.