"We use the standard Rohloff chain tensioner (Rohloff Article Number 8250).
You would also need a different left Slider (our Article number 180127. (Price can be requested at your Riese & Müller dealer).
The Chain length then changes from 99 Links to 107 links. We use the same KMX X1 Chain on both bikes.
When I mentioned the pivot, I meant Haibike's way of tensioning dual-suspension bikes, i.e.:
I don't know if it's even compatible with R&M Delite. There's no dedicated point on the pivot arm where to attach it.
As far as the Slider, I think the correct term is
removable dropout, I don't know why they call it a Slider, German mistranslation maybe?
Anyways, I own such a dropout. I actually bought a set (left+right+screws), cost about €100.
It's the solution R&M is using right now to get tension reasonable. Recommended bolt tightness is 15Nm. You only get the bolts, no hardware for what the bolts screw into. Just saying.
R&M uses a standard Rohloff tensioner though I suspect it doesn't matter unless you use the Wipperman Connex 7E8 or something equally thick in which case you might be in trouble and need to double-check.