The #deniedmyvote, could have brought the turquoise party down to below 2014 levels?
In a word NO.
To get the popular vote down to 27.49% you would need another 1,892,816 people to have voted and not one of them voting Brexit Party.
Whilst we know that there are thousands who were prevented from voting and thats very wrong, I don't think we can claim it would have affected the popular vote to that degree. There is no evidence that the scale of those denied the vote runs to 1.8million.
We know what did change the election was the number of seats that went to the Brexit party because people voted for Change UK rather than the LDs. This was around 25,000 votes in the NE and Wales and 100,000 votes in the SE.
If there were a significant number of people denied a vote in a particular region who were likely to vote LDs this could have affected the outcome.
These numbers are much smaller than the numbers required to affect the popular vote.
The numbers required to affect the number of seats in other regions represent a percentage of the vote which would be much bigger.
I think its dreadful that people were denied a vote from a purely democratic right point of view. But to say that it might have been possible to keep the vote below 2014 levels is not true and unhelpful, but you could make an argument to say there may have been enough people denied in certain areas who, if they had been allowed to vote, might have been able to change the result.