From this article:
The Gambling Commission...:“We do not consider it necessary to intervene to prevent some players using technology to gain an advantage in terms of speed of information, provided it is clear to all players that this can be done.” Why not develop this idea and make all players aware of such opportunities?
There are still people who imagine it is a good idea to back to lay or vice versa and leave blind bets in the market, but it's not anything like the volume from past years. There are some who study form and wait to bet until the early stages of the race, to see how it is developing - they are only a couple of seconds behind live, obviously at a disadvantage, but not necessarily terminal. But the increasing lack of liquidity makes this a less attractive as time goes by.
I think they only way forward is to stop the 1 sec delay on bets going in the market. The casual punters will get what they click on rather than not getting matched unless the market has moved away from them. Whether the bots that operate in the IR market can still make a profit without cancelling bets before they are taken is the issue that vexes betfair (so the rumours have it) as they would maybe leave the market further affecting liquidity.
I doubt they will ever turn off the one second delay. Unless they turn off online betting, i.e., don't use any networks to accept bets. Otherwise, how do you avoid the natural delay?