...Indeed it offers the opportunity to break your journey and max out time in the Lounges if travelling 1st Class.
You are not allowed a
Break of journey on an
Advance ticket, however a visit to a lounge is not within the definition of a break of journey - so you're OK!
I'm going to have an interesting situation like this soon. I have a Leeds - Edinbrugh AP with a change at York that is far too tight for my liking only 9 minutes. Given the high frequency of Leeds - York trains, I'd rather get the preceding one and be a bit more sure of making the connecting Northbound train. But I have a reservation for the TPE, which is problematic. So it's almost the opposite case, it clearly is a connection but it is still reservable. Tickets routed EC & CONNECTNS.
There is no contractual term that you'd fall foul of. The example given of Stevenage-London isn't the only one. I'm sure a TPE Guard has informed me that TPE allow the use of appropriate connecting services, but I can't remember where/who now. I have found a reassuring post from a Guard which I've sent you via PM.
--- old post above --- --- new post below ---
I had a Elstree to Birmingham advance. Following advice from this forum I took a train an hour earlier than strictly necessary. I used that extra time for a meal at St Pancras
I did not deviate from my route or go sightseeing in London. I think it was reasonable and appropriate. I had my excuse ready. I needed the extra time for the underground at rush hour with heavy luggage. I think catching an earlier train to minimise the risk of missing a booked train is an unfortunate necessity with the punctuality of some services. In reality my ticket was not checked from Elstree to Birmingham.
.
This is reasonable and, I believe, fully permitted.
Without wishing to stray off-topic, I do wonder if the walk to the Met at St Pancras (at least 300m), followed by the walk from Euston Square (at least 500m) is actually sufficiently shorter than the direct walk via Brill Place/Phonenix Road (approx 1000m) to be worthwhile? (obviously the deep level tubes wouldn't be recommended for this journey with heavy luggage).
A bus/taxi would be easier, though not included in the ticket.
In the end I did not take my booked train from Euston either. It was very late so I took an on time later train. Following the usual advice from this forum I asked the train manager not the man on the platform. Best wishes, Stephen.
Again, it's sensible. If they'd enforced an unnecessary delay, they'd have upset a customer and potentially had to pay out compensation!