Hi Dodgy - yes, I reckon they all work on the same principle and it would work with most, but without trying it one each one, people should only use this on Tekin, and now HW! Thanks for confirming that, it will be very useful to a lot of the 12th and GT12 racers on 1S!
As you say, if you don't exceed the limit of the regulator, you're in. The limit if the regulator is the limit of the number of cells the speedo is rated for.
I found the original thread on this, so for those who love the detail, including notes from the Tekin guys themselves...
http://www.rctech.net/forum/electric...packs-bad.html