Impressed with the stand in terms of quality and ability. Couldn’t get the bottom cupboard stays (not the hinges) to fit/work, so ditched them as they’re not necessary (would be needed if the cupboard doors opened up, to hold them up when open, rather than downward opening as designed to).
Also had to drill some extra holes in the bottom back piece, as there are none as standard for routing wires out of the back. Seems to be designed for storage purposes only, rather than extra media equipment etc; however this is/was not a big issue. 

For reference, if you’re looking for an idea on suitability; the TV located above/on the stand is a 77” OLED weighing 29.6kg. No issues to report, in terms of bowing or rigidity. 
Sound bar is a Sonos Arc, which fits absolutely fine, although not perfect for an upwards ‘firing’ sound bar.