Not sure where you are located, but if you spend the majority of your time in a other EU country (e.g. Germany) you will have a very hard time explaining to the local tax authorities that the company entity is not effectively being managed from Germany. And when you fail to explain this, the company entity becomes a german tax resident and you have to deal with all sorts of paperwork and expensive tax consultants. This is especially true when you have no local employees in Estonia.