I've struggled several times to formulate this question properly. I'm not convinced by your formulation. I'll give it an other try.
Does space have an existence per se, that is regardless of the matter it contains, or is it just a mathematical framework for the interactions between particles?
This requires a definition of space. For your question to be logical, space should be taken as the thing that is among and around matter. Then on it may be researched physically. Buf if space is taken to mean the thing that exists among and around perceivable matter, then your question becomes obscure, as this means that space is matter, but just not perceivable. And therefore it exists, also without relation.
We know what space is, at least operationally. Or rather space-time. Space is what can be measured with rigid rods. Time is what clocks measure. Einstein painstakingly defined those concepts this way.
Plank's question is more metaphysical : beyond what it means experimentally, does space have a -physical- existence per se, even in a completely empty universe? In other words, is an empty universe different than no universe at all? If not, one way to look at space it is to consider it as a set of abstract rules regarding the possible interactions between particles, those rules being very close to what we call geometry.
Does space have an existence per se, that is regardless of the matter it contains, or is it just a mathematical framework for the interactions between particles?