I would suggest that you folks not adjust your drive chain TOO tight. Meaning, it is better to err on the side of being slightly loose, than to have it be slightly too tight.
Yes, these 520 chains on the Van Van can wear sooner than a quality 525 chain, but a lot of that excessive wear has to do with over-tightening the chain, and not lubing the chain.
Personally, I install a ScottOiler on ALL of my chain drive motorcycles, and it really pays off.
Second, I plan to replace the front and rear sprocket when this original chain is done, and install a 16 tooth front sprocket, and a 45 tooth rear sprocket, both in the 520 size, along with a quality 520 chain.
Example of experience: Last Summer, 2018, I rode my 2017 Suzuki V-Strom 650 XT, aka the Wee-3 XT, up to the Yukon, and Northwest Territories, up through Inuvik, and "almost" to TUK...Tuktoyaktuk, NWT.
On that ride of 5,800 miles, the drive chain started out from home with 3,200 miles on it, rode 5,800 miles on this trip, and arrived back home with 9,000 miles on the bike. During that 5,800 miles, I did NOT have to adjust the chain at all, not even one time, but I was also using a ScottOiler, on an O'ring chain, simply to keep a slight flim of lube between the chain and sprockets.
Years ago, on my wife's 2001 Honda Shadow 750 V-4 Magna, she got 10,000 miles out of the OEM chain and sprockets. When I replaced them all at 10,000, I installed the same brand and quality of chain and sprockets, but also installed a ScottOiler Touring model, with the larger reservoir.
That bike got 40,000 miles out of that second set of chain and sprockets, with the same rider doing all those miles...and the same mechanic doing all the adjustments.
I will predict that once I install thew 16 tooth front sprocket on our two Van Vans, and using the ScottOiler, we will see in "excess" of 20,000 miles on each of these bikes, while still using a 520 sized chain.