any way to mange screen & data fields with the app or computer?

The only way to manage the screens is on the device itself.  Surely once you have set them up how you want them you won't have to change them again?

not really esp if you use it on watt bikes and new sensors etc. The default setup is pretty basic.

I suggest making different profiles.

one for your watt bike, one for outside, etc.

all you have to do then is simply switch profiles.

Totally agree with setting different profiles to avoid having to make changes each time you ride. I'm pretty sure there is a Indoor profile already installed on the 530 by default. 

By default there are Indoor, Road, and MTB profiles.  These can be modified and you can create your own profiles.

You need a profile for each type of bike/activity.  Then you just use the right profile for what you are doing and the screens will all be how you want them for that activity once you have set them up.  Sensors are not linked to profiles.  They all go into one sensor pool and the device will use whichever sensors are active at the time of the activity.

I agree with all the answers here, however I myself have been wishing for a less cumbersome way as well.

thanks - already understand and use indoor / outdoor profiles. Each has 8 to 12 screens with 6 to 12 fields each so just trying to find an easier way to manage them. And create 2 more indoor ones (smart trainer, rollers, Wattbike).

Even editing 1 field is tedious as you only have up and down.

It would be great if this could be done quickly from an app or god forbid the Garmin connect app.

You can adjust the number of screens in the profiles.  You can have only one if you wish.  This is true of the data fields too.  You can have a minimum of one per screen.  It is a bit tedious setting them up but once you are happy you don't have to touch them again.