I am from Germany and have a Mini 4 Pro. All sub-250 gram drones (also C0 classified ones) don't require remote id here and the actual firmware for my Mini 4 Pro doesn't support it yet.
However, if I would like flying with extended batteries and...
Don't think so, it is C0 class drone like (I don't have mine here, so cannot check if it got C0 or is a legacy one) and that class is not required to broadcast any ID in Europe. A C1 class drone has the possibility to enable it. One thing I have...
SDK / Third party apps aspect
At least each recent generation of drones got now a "pro" version of the RC. The remaining big question mark is what drones / RC pro 2 will be included in next SDK version so it can be used by third party app...