"Member is explicitly initialized to its default value"
There are test scenes using current value of ruleset bindable on their BDL (example in TestSceneSliderSnaking's BDL)
Should be recognized as a normal protected method in its declaring class.
Also makes `CreatePlayerRuleset()` and `CreateRulesetForSkinProvider()` not-null to avoid unwanted behaviour with their derivers
PlayerTestScene
CreateRuleset