How do I recover from/reset after changing my bot's runtime?

[mareekuh]

The instructions say: 'Configure Composer to start your bot using runtime code you can customize and control. Leave the field below blank if you don’t require customization.'

and the field has the following content: Start command : dotnet run --project CoreAssistant.csproj

Since I've never touched this field, based on the instruction I am concluding that I do have a custom runtime... If I were to wipe this blank, how do I reset it back to the 'custom runtime' that was pre-created for me? Can we put runtime editing behind a model (requires a click to make edits) - this is an advance setting, on the very first page of Configure, with which a user can royally mess things up. Are we ok with this?