My experience with the Outex kit, installed on stock rims from a 2008 Suzuki DR650.
Installed late 2021 @ 38k miles on the odometer, with minor prep of the inner wheel/rim surface: smoothing the rough weld seam and cleaning with mineral spirits. Followed the instructions from the Outex kit. I run pressures in the mid-30s and don't adjust for offroad. Riding environment is southern Arizona USA, high-speed (for what it is) freeway burns and offroad day trips on fairly tame 2-track. Zero issues, zero leaks or punctures. Tires are Dunlop Trailmax Missions in stock sizes.
Mid-April of 2024, I departed for a RTW ride from Arizona, bike shod with new Trailmax Missions, pressures at 35 front/39 rear cold. About 90 lbs of travel gear between all of the bags and boxes. 200lbs of rider including gear. 6.5 gallon fuel tank. I have a TPMS installed (Sykik Rider from Amazon) with fresh batteries installed in the sensors. I made it to Islamabad in early July, having lost about 5 lbs of pressure in both tires...I didn't need to add air at all. Riding conditions were pretty much a bit of everything: Primarily tarmac at moderate speeds, with some gnarly offroad in the Balkans and pavement of varying qualities as I went through eastern Turkey, Kurdistan and Pakistan (especially the southern part).
At about 11k miles on these tires, there is still about 15% of usable tread left (eyeball estimate...we all know the last bit goes away faster than you'd like/expect.)
Summary: The Outex kit has treated my very well, particularly coupled with the Trailmax Mission tires.