To safely create your own power and throttle response maps (they are typically two independent tables) you really need to be intimate with the strengths and weaknesses of the entire drive system. Without this, you'd be probably just as likely to create maps that do more harm than good. I don't think Alta is quite ready to divulge this kind of performance data yet. I'd think at first they'll release a tuning solution that allows the rider to pick and choose among the existing power, braking, and throttle response maps and allow only those combinations that have been proven to do no damage. I believe this could be done today as I suspect the display is wi-fi capable already. it just needs to be enabled via a firmware update.
How many of us would feel comfortable populating a typical 20x20 (400 cells) fuel map table for a typical ICE bike? Same for timing and all the various trim tables? With the help of a dyno and the proper instrumentation (exhaust analyzer, knock sensors, etc) one at least has a fighting chance to create decent maps (ie, good power, good fuel economy, good drivability, and SAFE operation). Without the proper instrumentation and knowledge of what each parameter measured implies in terms of performance and reliability your stuck with the proverbial "seat of the pants" analysis. The use of this process alone is probably the number one reason for blown ICEs.
Given "unlimited" ability to access and modify battery discharge rates, motor amps, and ramp rates without any regard to the inherent thermal, electrical and mechanical limitations of the system is a recipe for a burnt motor at least and possible destruction of the entire bike in the event of a thermal runaway.
I'm not saying we shouldn't be able to do it, but we first need a set of "rules of thumb" to guide and constrain our decision making process. Just like air fuel ratios, combustion temperatures/pressures, intake air temp, detonation, fuel type, etc, help guide the ICE tuning process. There's simply not much data available as are the means of obtaining the required data. We (the tuning community) need to begin the process of establishing a database of knowledge just like the pioneer ICE tuners did "in the day". It can be an expensive experience (failures) but if done incrementally and responsibly a set of "rules of thumb" will evolve.
Unfortunately, Alta is holding the key for any independent progress along these lines. Without access to real time and logged operating data and the ability to modify the tables and parameters that influence performance we're kind of stuck. Same for advances in battery packs. I'm sure there would be several aftermarket companies interested in building custom "to customer spec" packs. However, it's more complicated than just connecting + to + and - to -. I'm sure there's Alta specific protocols and handshakes that must be made between the pack and the main processor, BMS checks, etc, that must be validated before the system will initialize. Without help from Alta it would be difficult to emulate or bypass these steps.