Support finger input sliding between virtual face buttons on touchscreens

[untitled-operator]

I've noticed that the virtual D-pad lets you slide between directions without lifting your finger, but the face buttons don't seem to work the same way.

For example, in Super Mario Bros., you normally hold run and roll your thumb onto jump. Currently, the face buttons stay locked to the initial press, making this difficult.

I've reproduced this in both RomM (EmulatorJS 4.2.3) and the latest EmulatorJS nightly demo website.

Is there an existing setting for this, or could support for sliding between face buttons and overlapping button presses be added?