Hoe do I install apps manually from SD Card in Windows 10 Mobile?
I don't think if its possible now, but you can install xap or appxbundle from PC using Application Deployment app.
Not sure if they will add it back because they removed 'download' to PC option too. If you have access Windows desktop, try the tool I mentioned in previous post.
I hope that this feature is added in the subsequent builds. BTW Thank Gou for the information buddynow there is no limit for mobile data download in store