insufficient memory - How can I move apps to SD on non-adopted Marshmallow storage?

Everyone seems to be getting excited about Marshmallow's adoptable storage feature, but to me it seems like a major regression. There can be several reasons for not adopting external storage:

1. When upgrading from Lollipop, I already have an SD card full of stuff. So re-formatting it and erasing everything in order to convert it to adoptable storage is a major disincentive. That would require transferring many GB of data off the device, re-formatting, and then transferring it back on, and I'm not sure how to do that in a robust manner or whether it's even possible, since adopted storage probably stores stuff in different ways.


2. My SD card might be too slow for it to make sense using it as an extension of internal storage.


3. I want to be able to use my removable SD card in other devices (e.g. quickly transferring huge video files to a laptop).

Based on these reasons, if I don't adopt storage, AFAICS that means that apps can only be stored on internal memory. And since I have a lot of apps, that means that since the Marshmallow upgrade, my device is regularly close to full, causing lots of functionality to break.

So is there really no way to move apps to non-adopted external SD storage on Marshmallow? If so, do I have any alternative besides uninstalling apps to free space, or downgrading to Lollipop? If not, this would be hugely disappointing and suggest that Google really didn't think carefully enough before providing this feature.

Answer

You are correct. Android Marshmallow has done away with apps being on the SD card when it's setup as portable storage. The only way to use it in that way is with root and apps like LINK2SD.