Also very interestingly, there is very different advice for the evening peak restrictions. On GWRs website, it says
Not valid for travel from London Paddington between 16:00 and 19:15 except on all TFL services and the following GWR services:
- 16:56 to Maidenhead
- 17:27 to Maidenhead
- 17:56 to Reading
- 18:26 to Reading
- 18:49 to Didcot Parkway
- 18:56 to Reading
- 19:07 Bedwyn service as far as Reading
Half of which no longer exist or run at a different time.
On NRE, it says
Mondays to Fridays, valid from 09:30 or when Off-Peak Day Return is valid (whichever is earlier).
- 16:00 (16:27) to Bristol Temple Meads
- 16:03 (16:33) to Penzance
- 16:15 (16:41) to Swansea
- 16:30 (16:57) to Taunton
- 16:33 (17:04) to Exeter St Davids
- 16:45 (17:11) to Swansea
- 16:52 (17:20) to Oxford
- 17:00 (17:26) to Bristol Temple Meads
- 17:03 (17:32) to Penzance
- 17:15 (17:41) to Carmarthen
- 17:22 (17:50) to Hereford
- 17:30 (17:56) to Taunton
- 17:33 (18:04) to Paignton
- 17:42 to Cheltenham Spa
- 17:45 (18:11) to Swansea
- 17:52 (18:23) to Worcester Shrub Hill
- 18:00 (18:27) to Bristol Temple Meads
- 18:03 (18:33) to Penzance
- 18:14 (18:42) to Swansea
- 18:22 (18:50) to Hereford
- 18:30 (18:56) to Weston-Super-Mare
- 18:33 (19:03) to Exeter St Davids (Mondays to Thursdays) / Plymouth (Fridays)
- 18:37 to Cheltenham Spa
- 18:45 (19:11) to Swansea
- 18:50 (19:23) to Oxford
- 19:00 (19:27) to Bristol Temple Meads
- 19:03 (19:33) to Plymouth (Mondays to Thursdays) / Penzance (Fridays)
- 19:15 (19:41) to Swansea
Which are all very out of date times, and you'll also note that it doesn't state what the significance about these trains are, we obviously know they intend to say that it isn't valid on these trains but this is not clear at all.
On railrover.org, it says
Not valid on inter-city services that depart Paddington between 16.00 and 19.15 or Reading between 16.27 and 19.41
Obviously this is an unofficial website, but it also interestingly states that it has restriction code B1 which is just a blanket nothing before 09:30 and nothing else restriction.
Therefore, while I wouldn't advise it, it would probably be possible to use this ticket on evening trains if you are willing to put up with having to persuade the staff on the ticket barriers that you technically should be allowed to take the train
edit: what it says on NRE above is also what it says for the thames branches day ranger (as in a list of out of date trains). I would ask the question, if I buy this ticket and then say attempt to board the 17:07 service from Paddington to Reading which is usually a peak service, but isn't mentioned in the list above (and unlike most, there isn't a train to the same destination a couple minutes before or after) and then I show this list to the gate staff at Paddington, would they let me through?