Hi,
From a practical perspective, we have sites that have over 80,000 customers and they are using Adagio (and were using Adagio with 8.1 version) before we did upgrades to 9.2A. But we had speed issues when on a traditional LAN, with that volumes that high as we started to do upgrades to versions 9.x.
For this specific client with 80,000 customers, we were running our LInk2POS that integrated to the Windows Dynamics RMS POS solution, as well as integrating into Adagio OE. Most POS systems do not have to deal with volumes of this magnitude, but previous versions of Adagio 9.2A can handle it. We don't know about the next release versions (9.2B), but Softrak can address that.
To run any volumes of data using Adagio today, you should be running Adagio on an RDP server. (Period)
We have had sites that have been using over 100,000 items in Adagio inventory, but that was a while ago.
Best,
Brian