Yes, Hi-Fi audio is support.
Loola, while running under Chrome encodes audio using the following parameters:
Channels: 2 (dual stereo - left/right)
Sample Rate: 48 kHz (full band)
Bitrate: 128 kbps
No additional audio processing is performed (such as auto gain control, noise filtering, echo cancellation etc.)
All platforms except Instagram play the audio as received from Loola. Instagram mixes both channels to a single mono audio (Instagram doesn't support playback of stereo audio).