You can properly shoot at higher frame rates. We are handling this like SMPTE suggests in its latest issue of the specs:
Just use your Tentacle unit with 30 fps (29,97 fps, 25 fps), when recording 60 fps (59,94 fps, 50 fps). Our Tentacle Sync Studio software will automatically detect the difference and will recalculate the timecode for the higher frame rate.
We developed our Tentacles in relation to international broadcast television systems. This means that they work with standard SMPTE 12M timecode. This standard has been invented long before the introduction of any high frame rate formats. Technically speaking, our devices do not support any frame rates higher than 30 fps. This is a technical limitation which we can't change. We still have to meet the technical specs of other timecode devices to be compatible with.