Short phones got no reason. 
APK files will work but it can be a challenge finding the specific one that is right for your specific phone and Android version. And, you will have to shut off automatic updates so that the version you install doesn’t get clobbered with an update.
I have stayed on Wyze App 2.50 on all of my devices (just never updating to 3.xx). I have Automatic updates turned off but update other Apps manually regularly.
As far as choosing the correct APK file I mentioned 5 posts above, I just grabbed the last and most recent 2.50 version on this site (which has been working great on my Fire HD 8 tablet).
There are only 2 Wyze app versions of interest; version 2.50 and earlier run on any 32-bit Android, and later versions run on 64-bit versions. You only need to determine which type of Android your phone has.
If you have a 32 bit phone you don’t need to disable updates, it will not update to the 3.x app. Actually the easiest way to install the 2.5 app is to grab like the second to last version which is a raw apk file and doesn’t require the apkmirror installer, then just go into play store and do an update. You’ll get the latest/final 2.5 app.
The SD card slowness is annoying, but when I need to look for something I use the old 2.5 app (also on an old phone that is wifi only, but it is a 32 bit phone and only works with 2.5). The issue doesn’t exist there. The OG is still a great cam, hopefully they resolve that bug soon for the 3.5 app.
Not to worry. Wyze is introducing the all-new Wyze Potato Slicer and Wyze Toilet Brush that will revolutionize your Wyze experience.
I’m still waiting on the Wyze Crapper (Bidet Toilet Seat)
“Sorry we can’t clean your ass until you perform the update”
I just hope it won’t be a single unit 
Yeah, I know you’ve been waiting well over a year for that one. 