The corner is never used and I'm not sure the stand has ever held that much in recent times.
The Sheffield Advisory Group have made recommendations in recent seasons that the allocation needed to be reduced. There's only around 1,300 allowed in the bottom which means all seats aren't sold.
This had never been an issue in recent times as Wednesday, Leeds, Sheff United, Arsenal etc had all managed to allocate around 4,000 in the stand with no issues. Newcastle turned up, caused a stink online which was supported by the media and the deductions were later applied.
That concourse is quite cramped from memory. And in fairness it isn't just Newcastle supporters who've raised concerns about Hillsborough recently either. Leeds, Sunderland, Coventry, Plymouth, Bolton and Port Vale. There was an article about it in the Athletic which I don't personally have access to. However, said article was quoted and discussed on Owlstalk in August. While I haven't read the whole thread this extract comes from the quoted article which covered our last visit..........
'The Athletic attended Wednesday’s final home game of last season to experience the Leppings Lane end first-hand alongside visiting West Bromwich Albion fans. West Brom were bidding to retain their spot in the Championship play-offs, while Wednesday, who had been mired in the relegation zone all season, needed a win to lift themselves clear of it.
West Brom brought 2,400 fans, filling the upper tier. The lower tier, slightly unusually, was being used by Wednesday fans. Outside the ground, there were no apparent issues, with fans flowing freely into the Leppings Lane end.
In the aftermath of the Newcastle incident, several complaints about signage were made on social media and to the Newcastle Supporters’ Trust. Pictures of the area while empty had made the signage appear clear. However, in practice, the upper concourse’s long and thin shape, with signs mounted on the wall next to each gangway, rather than overhead, meant it was difficult to see any numbering except for the exit directly beside you.
Before kick-off, there were long queues for each of those gangways — but that is not unusual at football grounds across the country. Instead, the most troubling moment came in the centre of the concourse around 10 minutes before the game started.
The away end’s bar, situated in the middle of the space, narrows its width even more, with toilets located at either end. At one point, the crowd stopped flowing, tightly bunched in a group of supporters, shoulder to shoulder and unable to move. It was only for around 60 seconds — and felt uncomfortable rather than explicitly unsafe.
There were no issues at half-time — where the main anger was the lack of food and drinks in the away-end kiosks — and similarly at full time, though Wednesday’s 3-0 win meant that the majority of West Brom fans had left in dribs and drabs throughout the second half. By the memorial to the supporters killed in the Hillsborough disaster, a West Brom fan had neatly folded a shirt as a tribute'.
....... link to the thread provided, a quick scan of the first few comments from Sheffield Wednesday supporters suggests they're not entirely comfortable with Hillsborough either.
https://www.owlstalk.co.uk/forums/topic/332526-long-read-the-athletic-investigation-into-hillsborough/