KTL define an area-elastic floor as one with a wide area of deformation when it is put under pressure, and they place that deformation below the floor surface. The advantage they list for it is a high level of stability whatever the load. Their other option is combi-elastic, which is a synthetic covering over the same kind of subfloor and which they describe as adding resilience at the surface itself as well as below it. That distinction is the whole ballet question. Structure that gives under a landing is what a dancer wants. A surface that gives under a pivot is not, because the shoe sinks slightly and the foot grabs instead of releasing, and KTL's own dance ratings follow that reading.
Recount the dance row and it splits cleanly. Five systems are rated very suitable: FlexiPRO 12 V3, PRO III, PRO II V2, Multiflex Advanced V2 and Multi Clip, and all five carry a solid KTL hardwood surface over resilience that sits below it. The two portable systems are rated suitable. The two lowest marks in the row both belong to FlexiPRO 21: less suitable with a 2-4 mm non-resilient covering, and unsuitable with a 6-9 mm vinyl or PU covering. That unsuitable mark is the only one in the dance row.
KTL's own recommendation for this class does not follow their own ratings, and the honest thing is to say so rather than quote the half that suits us. For their Studio and Yoga class they name one synthetic option, FlexiPRO 21 with a vinyl, PU or Lino covering, and the FlexiPRO 21 system page names dance and yoga studios in what the system is designed for. The dance row then gives those two builds the lowest two marks in it. We read the matrix as the more specific statement, because it scores dance directly rather than a class of rooms, and we would put the conflict to KTL in writing before specifying either way. Either way, one fact travels with that system: KTL supply only the birch plywood subfloor, so the covering that carries the classification is a third-party product.
The load case sets the floor rather than the shortlist. KTL define their Studio and Yoga class by light load and transport of equipment, and a ballet room carries dancers, a barre and a piano, so standard point and rolling load is sufficient here rather than a compromise. On its own it rules nothing out, and one of the candidates below carries high load capacity anyway. What chooses is build height, because a studio is usually fitted into an existing building with a fixed door threshold and a mirror wall landing on the finished floor. Across the five systems rated very suitable for dance the builds run 32 mm for Multi Clip, 39 mm for FlexiPRO 12 V3, 52 mm for Multiflex Advanced V2, 64 mm for PRO II V2 and 76 mm for PRO III, and PRO III rises to 96-156 mm once it is on wedges. In a retrofit the tallest of those is out before its performance is discussed.
The certificates are worth reading precisely. FIBA licences are issued per system and by number: WF73-06 for FlexiPRO 12 V3, WF73-03 for PRO III, WF73-01 for PRO II V2 and WF73-02 for Multiflex Advanced V2, all four stated as FIBA 2020 Level 1, and they are basketball approvals. BWF Grade 1 International Elite is badminton, and three systems carry it: PRO II V2, Multiflex Advanced V2 and Portable PRO. Neither body says anything about dance, and EN 14904 is a sports floor standard with no ballet classification in it. KTL publish class letters and no shock absorption, vertical deformation or friction figure at all, so a dance brief written around a deflection number cannot be answered from this catalogue.