Background to Foreground Exchange

I have an interesting challenge. I think there is an easy solution, but I'm drawing a blank right now.

I have a background process that grabs a JSON payload from a makeWebRequest. The amount of data I need to transfer back to the foreground it too large for either the "exit()" method or using the Storage method. So I break up the data and use both. That works great.

But the EDGE 1000 (among other older devices) are pre API 3.2.0 and can't use Storage from a BG process.

So, I need to rearchitect the approach. I could run the BG process twice (waiting 5 mins between instances) and transfer part of the data then the rest the next time. But that means waiting 5 extra minutes. Plus I'm not sure how to inform the BG process which part of the data I need, which it already sent the prior time. Since it can't access a Stored Value.

Any tips on how to approach this? I'm sure this is a common pattern, I'm just blanking right now. THANKS!