Unable to invoke target method in current thread. Use `BeginInvokeOnMainThread` method to prevent this error

 When I try to execute any cAlgo method from another thread I get this error:

Unable to invoke target method in current thread. Use `BeginInvokeOnMainThread` method to prevent this error.
   at cTrader.Automate.Host.Runtime.Instances.SmallAlgoInstanceBase`1.HandleDispatcherUnexpectedThread()
   at cTrader.Automate.Host.AutomateTargetSessionController.OnDispatcherUnexpectedThread()
   at cTrader.Automate.Adapters.SymbolApi.SymbolsProviderAdapter.GetSymbols()
   at cAlgo.API.Internals.Algo.get_Symbols()

After a while I realized that cAlgo offers this "BeginInvokeOnMainThread" method. Although that only executes some code asynchronously in the main thread there is no way to return a value from it.

After a while again I noticed how messed up is this thread model in cTrader 4.3.

Basically every call seems to be checked if it is being executed in the main thread. 

I had created a bot that, for instance, on position open, it would do a GRPC call to another application which in turn could call ctrader to execute something like create a new pending order.

The issue now is that GRPC will execute in another thread in cTrader when receiving a call from another application. That other thread will need to access the main thread, which in turn is locked because of the GRPC outgoing call on position open. As a result I have a deadlock.

Any ideas on how to workaround that?

I don't get why it has been made this so strict way that everything must go through the main thread.