c) Whether the amendment is detrimental to procedural economy  

In T 2638/16, the patent proprietor had filed its reply to the grounds of appeal late (shortly after expiry of the period prescribed in Art. 12(1)(c) RPBA), its request for an extension having been refused. Exercising its discretion under Art. 13(1) RPBA, the board took into account that the reply had been received immediately after notification of the refusal of the request for an extension and so at a still early stage in the proceedings and that the belated filing had not prevented it from considering the complete cases of all the parties. It could see no indication that the late filling had been a tactical abuse of procedure or impaired procedural economy. It thus took the reply, and a document filed with it, into account under Art. 13(1) RPBA.

In ex parte case T 786/16 the request at issue was filed at a late stage of the oral proceedings before the board. Possibly unsearched features were added from the description, along with expressions which were not literally disclosed in the application as filed. The addition of the unsearched features further meant that the claim now included three alternatives, each requiring separate examination. The board noted that either an extensive examination of the new features with respect to compliance with Art. 83 EPC, Art. 84 EPC, Art. 123(2) EPC, Art. 54 EPC and Art. 56 EPC would have had to be undertaken at the oral proceedings before the board or the case would have had to be remitted to the examining division for further examination. In the board's view, neither of these steps would have been consistent with the need for procedural economy, even less so considering the primary purpose of appeal proceedings (Art. 12(2) RPBA).

For further decisions in which procedural economy was considered and the requests were not admitted, see e.g. T 136/16 and T 2112/16.