Sorry for the confusion - I was only able to alter the default settings on the IP logger by installing thee Windows Weatherlink software on a Windows PC which allows you to alter configurations such as the data logging interval from the default 30 minute value. I found those instructions in an older post on this forum. The PC Weatherlink software allows you to change that setting which is stored on the IP logger itself (not in the Weatherlink PC software or weathlink.com) so once the change was made I no longer run the Weatherlink PC Windows software.
Making that change for the default data logging interval from 30mins to eg 10 mins, allows the graphs on Weatherlink.com (v2) to have more granular data points. However the Weatherlink IP only seems to upload archived data to Weatherlink.com (v2) at the top of the hour, and at that upload all your data points for the past hour are then seen in any graphs. The bulletin page does appear to be real time data and not subject to the hourly upload.
Like you my home PC's are Macs, so I had to borrow a Windows PC long enough to load the Windows Weatherlink software to change the configuration on the IP data logger. Since Davis seems to be moving towards the cloud / web model ideally there would be a way to alter configurations that reside on the IP logger through the web page or phone app while on the local network.