Thanks for the extra information.
1) I think you're saying you want the GPS navigator (assuming you mean an in-panel GPS like a GNS430, GTN650, IFD440, etc?) and iFly to talk seamlessly to each other, using the iLevel as an intermediate device to provide the connectivity? I think that's unlikely to happen, for a number of reasons; Off the top of my head:
a) the iLevel folks would have to get involved to create the interface between the iLevel and the in-panel navigator. That alone is probably a non-starter. At the least, it's out of Adventure Pilot's (iFly's) control.
b) iFly tries to work as consistently as possible with all ADSB devices. iLevel is just one particular ADSB device; creating this linkage as a one-off capability with that one device would be kind of strange and not consistent with iFly's "works with lots of devices" strategy.
c) If I was right about the types of in-panel devices and you're thinking Garmin GNS430s and GTN650s and their cousins, that's probably a non-starter because Garmin doesn't play nice with others. They're notorious for not supporting interoperability with other brands unless they've got a specific deal with them. iFly's approached them before for other potential collaborations and they've been rebuffed. That means there's not really any "common point universal to all navigators", via iLevel or anyone else.
d) Other brands, like Avidyne and Dynon, have more open interfaces designed to allow flight plan sharing with devices/software like iFly. Avidyne has its own wi-fi that iFly could connect to, and they allow both flight plan and ADSB data to flow out to those secondary devices/software (but the ADSB solution would be one that works with the Avidyne box, and that's somewhat limited). iLevel would not be part of that mix--iFly would either be connected to the Avidyne box, or the iLevel, but almost certainly not both. (Adventure Pilot/iFly has said for years that they plan to support FP/ADSB sharing with Avidyne navigators, but that capability has not yet been developed.)
I also don't think you're going to see iFly draw the magenta line exactly like the in-panel navigators, because only the waypoints would ever be shared, not the detailed lines/curves drawn by the navigator. iFly actually does its own "smoothing" of heading changes, and those pilots flying experimental planes who have dedicated iFly devices driving their autopilots will see their a/p's fly a smooth transition at heading changes based on the signals sent by iFly. It just doesn't draw those smooth curves on the screen.
2) Like I say, maybe Brolin can offer some more detail on this one.
3) I remembered your Lynx issue and my response took that into account. My point was that if AP/iFly was going to make a change to the code, it would be better to change the code to fix the bug instead of slapping a bandaid on the problem and make the user flip a switch to disregard bad attitude data. It's possible that fixing the bug could be an easier/quicker solution to your problem than creating new menu options/user interface changes to implement an "on/off switch", and it would be more elegant also. But of course that's just speculation (and personal preference) on my part.