The other option for RC was the Novak Sentry, which has built-in accelerometers.
The data from the Sentry was a little noisy, due to cheap sensors and lack of precision on the data storage. But in general it worked well; I used one for years when we were running 13.5 boosted as it was really useful getting an RPM trace to adjust boost and turbo.
Discontinued now, but you may find one around somewhere.