Hi evert.
I can't quite remember the specs on the 10+ right now, but seem to think it will be of thicker wire diameter than the standard TX spring?
What power are LGVs usually set up for over there? As you know, the JT tune is a sub-12 tune and they do shoot very, very sweetly.
I have in the past tried other mildly fettled LGVs which also did shoot very nicely indeed. Fitted guides and a relube by someone as experienced as yourself will result in a most pleasing rifle.