Upgrading to BIAS FX 2 Std is not required to use RIFF but to have a higher license tier for BIAS FX 2 will definitely open up more downloadable presets in ToneCloud.
If a preset contains any effect/amp that is not available under your current license, you will not have access to the said preset. For easier navigation, you may change the ToneCloud navigation set to 'Available download only'.
For further information, please check [Effect Model List] and [Amp List] in BIAS FX 2 section in our help center.