You have to consider what the app or device is doing to know if it's an issue. An outlet with a ton of runcounts would lead me to think power reporting is too frequent. Or say a local motion app with a very high run time, you may want to reconsider how you structure it. A motion sensor with lux enabled and a ton of runcounts would also be a good example where you could flood your mesh. Or a contact sensor with an average run time of 300 is probably a problem.
Local apps tend to have a runtime of around 150 or less and usually around 70 while cloud enabled apps can be much much higher depending on what they are doing.
If you have very high runtime apps consider what they are providing and make an educated evaluation about whether the load is worth what they are providing. Especially if it's not showing an impact on your automations. Then if you do have a problem with them in the future you have an idea of things you can disable to track down the source.
Devices on the mesh are going to be more impactful because of the bandwidth limitations of zwave and zigbee. Lan is less of an issue because it's all on the cpu, memory, and local network.