Several bugfixes and improvements (I.E. retrieve process status in bulk, more accurate response codes, improved offer export performance and higher rate limits for shipping label endpoints) have been done lately to improve operations on the Retailer API v3. Thank you all for your input. We also scaled up our services to offer and maintain a better performance level.
With most of the API users migrated to the v3 we are ready to keep improving this channel together with you, every day.