The app I’m building uses the bottom tab menu for the more functional aspects of my app and the side menu (from the upper left hamburger) for informational aspects of the app. When navigating areas of the app accessible from the bottom tabs, you can let the user get lost in a multitude of linked pages, because tapping the bottom tab buttons always takes them back to the home menu. However, the side menu of links are not so friendly. The page covers the bottom tab buttons completely and so your only way back out to the main menu is “< Back” and possibly “< Back” and “<Back” and “< Back” and so on depending on how deep the user has been winding through relational links, etc. A simple “Close” button on the upper right of screens from the side menu would allow users to simply close out the side menu and return to app’s main home in one click. I realize this might be tricky if an editable Detail Page is put in the side menu (the little pencil would have to move), so maybe an alternative is to allow the bottom tabs to stay visible even on screens from the side menu.
I second that. Bottom buttons should always be visible.