If the fraction display setting of a math region is not changed from default, then the check mark indicating the current setting is missing in the context menu. This is inconsistent with the handling of the other display options (decimal places, exponential threshold). As soon as the setting is changed (or confirmed) in the context menu, the check mark shows up.
Not critical, but perhaps easy to fix.

Martin Kraska
Pre-configured portable distribution of SMath Studio: https://en.smath.info/wiki/SMath%20with%20Plugins.ashx