What would also be good would be GWR▸ automatically refunding people for tickets purchased through their website - for example in respect of an advance ticket for a particular train which is then cancelled/delayed, rather than customers having to go through the rigmarole of claiming for it.
Automatic Delay Repay is offered by Virgin Trains (West Coast) for Advance Purchase ticket holders who purchased from them online.
Smartcard users on c2c receive automatic compensation for delays too. Their scheme kicks in after just 2 minutes delay! 3p per minute for 2-29 minutes, then standard Delay Repay rates from 30 or more minutes. Credited to your Smartcard account for use against future ticket purchases, or converted to cheque (£5 minimum) on request.