There is a Can Bus protocol imbedded in the BMS for the M600. It probably has an affect on the throttle function. This is a new move by Bafang to come into line with the manufactured products by the EU manufacturers. However, unlike all Bafang products that have come before that are DIY user friendly it does make things less so. This helps to explain Can Buss communications and although they don't specifically mention eBikes be assured that it is being used in this sector and going forward more so on the manufacturer level: https://www.csselectronics.com/screen/p ... ies-Basics
Luckily they are forthcoming with the protocol which as far as I can tell others aren't as proprietary control of their systems is important for them and are unlikely to be shared.
I would wait for the M600 battery you have on the way before coming to any conclusions and know that any future developments will be supported by Bafang as I understand it. Although Bafang support is not noted for it's quality when dealing with them it is the hand we are dealt to avoid having to deal with say Bosch, Brose, Yamaha etc. that would go nowhere fast. At least they are reachable and their interest is in gaining market share in the evolving OEM eBike market. However this is going to be interfered with via the trade tariff's somewhat if the cost becomes an issue.
I would like to add that integrated battery systems I feel are limited for future upgrades in battery technology. This also leads towards the realm of proprietary components instead of the open source ones that ES has been about all along with the ability to adapt or modify to new tech as it comes along. Especially with the 2170 cells on the near horizon that will not fit in an integrated dt unless it is designed to and not be retrofittable.
Meanwhile the geometry of the frames showing up that will hold the M600 are not up to modern standards as far as I see it. This isn't a huge issue but why not get the best handling bike possible out of the deal also? It is also important for larger market appeal if they are more in line with their analog counterparts and what the cycling public has been led to expect from "next years" model. While in the end it may or may not have enough effect on the handling of the bike for the average cyclist, perception rules in the bicycle marketplace.