iOS Question How to use a ios app wrapper

You do need a local Mac to create wrappers. If the SDK is simple enough then you can access the native APIs with NativeObject or a bit of inline OBJC (you will still need a local Mac for this).
[Objective C] Writing libraries for B4i

Short resonse:
I now bought a mac mini 2011 with High Sierra 10.13.6 and installed Xcode 10.1. I'm now able to run the wrapper and wrap my apps. Thanks you for your efforts.

I have at least one question about it:
The wrapped app could receive app-specific configuration from the server. It should be possible with implementing the followong callback methods on the class that implements the UIApplicationDelegate protocol:

objective-C:

-(NSString *)appConnectConfigIsNSDictionary *)config;
-(NSString *)appConnectConfigChangedToNSDictionary *)config;

Swift:

@objc func appConnectConfigIs(_ config: [String : Any]) -> String?
@objc func appConnectConfigChangedTo(_ config: [String : Any]) -> String?

The documentation says: "The parameter is an NSDictionary object which contains the current key-value pairs for the app-specific configuration."

How could it be possible to implement this in an app?

Example of modifying the application delegate class: https://www.b4x.com/android/forum/threads/add-quickactions-to-your-app.74263/#post-556975
(post #3).