So I'm doing some stuff with Intercom and their editor is really wonky for custom HTML emails.
It strips out stuff when you add HTML in editor and adds in something, not sure what exactly, that makes Outlook have extra space between columns.

Naturally, I use tables for multiple column sections, as they had better support for quite some time, ever since that KitKat update on Android.
Since I just can't make that render good on Outlook from Intercom, without screwing it up everywhere else, I tried to go the old td route for multiple columns and use display: block; to make them stack on mobile.

My mobile tests:
Gmail App - all good
My Android client (Boxer) - all good

iOS never had any problems with that, so the 2 main reasons why display: block wasn't as good to use are now no problem.

Anyone using display: block; for column stacking on mobile?
Is it safe to assume that display: block is back and is supported on various mobile clients/devices?

Let me know your thoughts.
Cheers,
Zoran