It seems BLS are in some sort of collaboration with Uk railtours as they have a Uk railtours diary date on their website and Uk railtours is selling the Toots Express
The BLS website is only ever going to attract limited interest enthusiasts.
As an aside, and I'm sorry to say it, but too many enthusiasts are only interested in one class of loco.... and real ale. That is never going to be sustainable in the long term and, as such, I think diesel and electric tours will become increasingly unviable.
So, because the train is clearly not selling well, the BLS have gone to UK Railtours to gain access to their database of customers who are more likely to be normal day out types more suited to this type of train. Problem is, are those passengers going to pay for a fairly early start and late finish just for not much more than two hours in Edinburgh? I don't think this is the start of a more long term association with UKR.
The BLS ought to stick to tours that sit in sidings for half the day, that is what they do well, is what their customers want, and always seem to sell well, and leave everthing else to the likes of the LSL group who do what they do very well and are also of considerably better value.