UKVCAS document checking - is it worth it?

We have received an email saying that our application is not eligible to reuse biometrics and therefore we must attend an appointment.  This is a bit of a blow as it means dragging the kids out of school for the day and both of us taking a day of work.  But hey ho. 

We were planning on scanning the documents ourselves, but when booking the appointment were also offered a 'document checking' service at a whopping £50 each to check the 'quality' of the scan.  Does anyone have any insight into what 'quality' actually means?  It doesn't seem that hard to figure out if the scans are blurry or not, so not sure it's worth paying the extra for.  That said, I don't want to have just forked out £6K only to trip up because we didn't pay the last few hundred to make sure they were 'acceptable'!

I don't think I've seen anyone use the Document Checking service if they have uploaded their documents at home, so personally, sounds like a waste of money to me.

As long as your scans are legible and meet the requirements (no bigger than 6 MB files, scanned in black and white or greyscale, and between 150 and 300 dpi), there's no need to get them checked.

Most people on the forum have either:
- uploaded their documents at home and not purchased any extras for the appointment
or
- paid for the document scanning service and had their documents scanned and uploaded by UKVCAS at the biometrics appointment

We have received an email saying that our application is not eligible to reuse biometrics and therefore we must attend an appointment.  This is a bit of a blow as it means dragging the kids out of school for the day and both of us taking a day of work.  But hey ho. 

What about booking an appointment at a centre that does weekend or out of hours (i.e. evening) appointments... if there are any available? That way you wouldn't need to take the kids out of school or take a day off work.