Your delay are for me “correct”.
By default, the panel is refresh every “5” seconds what seems correpsond to your 2-3 sec.
When you are on 4G, it’s by default slower so 10sec seems logic(regarding the default value) but I admit a little too much!
For the data traffic, I need to investigate, I already see that.
I have to focus on that, not for the next release but probably the next one.
For your DS115, you can use the property “use_stack” in the core service. Set it to “Y”.
It will manage your messages via a queue mechanism. Maybe it’ll increase your perf also.