This was an idea we had in mind (and discussed) somewhere a while back. Users should be able to pass defaults to a convenient method, so all the requests to the bot API which have this paramater defaults to the one the user provided. Examples would be parse mode, disable notification, hide link preview. This shall be edited with a sufficient list of parameters and where exactly we want to implement this (updater, dispatcher, bot instance?) in the future, this is merely a reminder for now.