It is reported that this aircraft was the only flying prototype of a design which first flew in 2019, noting that testing was delayed (runway repairs ?!) and that the next aircraft have significant structural weight reductions and uprated engines.
It is reasonable to assume that this aircraft had some of these modifications, and depending on resumed flying since March this year, that the flight envelope - handing qualities were not fully explored, e.g. assumed vmca, a range of configurations for a high lift wing, higher power rating. Added to which is our incomplete knowledge of the flight control system. The aircraft is reported to have an integrated digital flight-deck; so probable elect signalled, hydraulic powered controls, aileron / roll spoiler?
From the video so far, it is appears that as a result of a ‘system or component’ failure (opposed to loss of control), consequential damage from an un-contained fire, outside of the designed containment zone and/or extinguishing capabilities, i.e. not necessarily in the engine nacelle, and thence impaired control functioning.
The event - based on video #1, appears to have evolved over some time; ‘puffs’ of smoke, then fire, with uncharacteristic ‘flare’ ejections not normally associated with fuel only.
Such is speculation; but we must not classify events based on outcome or human activity, which often result in unrelated recommendations, unnecessary safety and training activity.