Check out the Asus ROG Zephyrus Duo 15, even though it's marketed as a gaming machine, it will address all the issues you're talking about and might even compete with the new MacBook pros that just came out this week. It should more than suffice since you use it for mostly dev and would be great value. I've personally reviewed it and YouTuber TechLead uses it. Check it out then do your homework before you buy anything, anywhere. Cheers.
https://www.4alltech.com/2020/06/the-asus-rog-zephyrus-duo-1...