I'm getting the update now. It's major, more or less a reconfiguring of all the games.
It seems Microgaming have implemented a number of the UKGC required changes. I don't know whether it's across the board, or whether it's done by geolocation so that UK players will have a UKGC compliant Viper client.
It may be possible to bypass the 25 limit, just as it was possible to bypass the 500 limit before it. Other than that, it just means one mouse click is needed per 25 bet block for autoplay. One advantage is that it's going to be next to impossible for casinos to claim that "autoplay was abused" when playing a bonus provided it's done in 25 spin blocks. No more watching a movie whilst the computer grinds away at the WR.
This is probably not the only change either.
I got a popup telling me the terms had changed, but a fault meant that they could not be accessed from the lobby link, it just loaded a blank page. This is another UKGC requirement, that changes to the terms must be notified to players, rather than leaving them to find out when it's too late by checking the website every few weeks.
Finally, I got a reworked popup telling me I had an unfinished bet, but when I checked the game, there wasn't. This could be another of the changes made to the software in order for it to be UKGC compliant. It will also help with those irritating moments when for some unknown reason, a cash deposit to a zero balance suddenly turns partly into bonus, leaving player and CS fumbling to find the cause.