Various narrow gauge Hitachi A train products for far eastern markets have tilt incorporated, including the 885 series for JR Kyushu, and a derivative for Taiwan. which look very similar to our IET.
https://en.wikipedia.org/wiki/885_series
The Hitachi system is a 'hybrid' technology incorporating powered actuators combined with natural passive tilt.
http://www.hitachi-rail.com/products/rolling_stock/tilting/feature05.html
They have managed to incorporate this within narrow gauge clearances that are in fact very similar to UK historical values on the conventional standard gauge network, and which feature a similar high platform.
https://ja.wikipedia.org/wiki/ファイル:Rolling-Stock-Gauge-in-Japan.svg
(Blue = older narrow gauge, grey = more modern narrow gauge, green = Shinkansen standard gauge)
Note Japanese trains designed for the narrow gauge (including mini-shinkansen services over branch lines converted to standard gauge) often incorporate a 'tumblehome', a narrowing of the car body just above the solebar level to clear the high platforms. This is very familiar feature to UK observers.
All lends weight to the theory that the UK's main line railway system was built to narrow gauge proportions in all respects apart from track gauge!