I can't help but feel there is some exaggeration in here. 20 minutes? That is a very long time. Last time I collected in bulk from an S&B machine (the same ones as the machine at Nuneaton), it took me less than 15 minutes to collect 20 bookings, all with separate reference numbers and have 4-6 coupons each.
Although you cannot have tickets for travel within 3 days posted out, I believe LM website still offers free postage if you are travelling more than 7 days away.
No, there's no exaggeration, nor rounding. I've timed it. It takes at least 30 seconds to get the credit card accepted, enter the booking reference and wait for the reservation to be found. Then it takes at least 120 seconds to print the 9 coupons (2 outbound + 2 reservations + 2 returns + 2 reservations + 1 collection receipt). Multiply that by 8 bookings and that's your 20 minutes gone, if you can have continued access to the machine. If I've got multiple bookings, I try to go down in the evening when the booking office is quiet.
I tried to collect a single Virgin booking (7 coupons) from Bournville station recently and the TVM is on the platform. It was exactly 120 seconds before my train was due, so I thought I had time as the trains to Birmingham are nearly always at least a minute or two late. Sod's law, however, applied, and the train came in bang on time. I got my first 6 coupons and then had to dart on board and abandon the collection receipt 130 seconds after starting the process.
On the other hand, when I can pick up tickets at Coventry, it takes about 40 seconds total to retrieve a 9-coupon booking. And the queuing time to get to a machine is usually nothing and never more than a couple of minutes (but that may be down to the fact I tend to be there when it's not busy).
As for LM postage, I started a thread on here some while ago about LM refusing to accept their obligations when tickets are lost in the post. While all the legal advice I received was that LM were in the wrong, the reality was that it was not worth the time and effort to pursue, so I simple choose not to buy from their website unless they have a sale on.