Things to look for on MkIII trafic?

[Wookey]

I'm going to look at an X82 (i.e 2014-onwards, MkIII) Trafic (camper) to replace my now 25-year old trusty mechanical-age Peugeot Expert, which still works but is getting quite tired at 194,000 miles (and 215,000 for the engine IIRC).
I know nothing about Renault engines, except the thing about the scuttle panel leaking on the MkII vans and welding your injectors in place. I presume they've fixed that on the MKIIIs? But is there anything I should be checking before parting with quite a lot of money? It's a 2021 (26,000 miles) 2.0L example (but it seems there are 3 flavours of '2.0 dCi' engine. How do I tell which I'm getting?). Wikipedia tells me it's an M9R I4, but then it say the MkII has the same engine, and various online reviews say the engine is 'all new' for the MKIII version. Who's right?

Cheers for any pointers.

[Wookey]

Just in case anyone cares, I've ended up with a 2017 X82, but unfortunately it says 'Vivaro' on the back so strictly speaking I no longer have an appropriate vehicle for this forum (even though it's a Renault trafic really).
That's a pity - I like you lot.
I'm still trying to get rid of the old expert so I'm not totally french-car-less yet. Any offer better than the £300 the scrappy has offered will secure the still entirely functional and actually very reliable camper van.

First fettling job has already come up: there is no gas in the aircon so I need to refill it, and probably find a leak. It's r134a (last year that was alllowed) so I can't just buy some of that, only various replacements, but most of them available in DIY sizes are very cagey about what's actually in the can and won't say so. One drop in replacement with less than half the GWP (687 vs 1430) is R456A but I can;t find anyone selling than in small cans either.

Does anyone know what all the dodgy outfits like aircontopup.com or vrjrefrigerants (ebay) are actually selling? They just say things like "This is not an HFC, it is a natural hydrocarbon. The product does not fall within the scope of the F Gas regulations - the coolant is not R134a. Instead it is a 100% compatible product that can be added directly to vehicles specified with R134a".

The thing is that only R456A (and the quite new R516A) are actually sold as a drop-in replacement for R134 without changing the oil. There are other mixes that will do, but some need different oils. But I've not yet found something which claims to be '100% compatible' and 'just a hydrocarbon'. So I'm very suspicious about what's going on here. There are video of it going in and working, so it probably does work, but I still want to know what it is and what the ifs and buts are.

OK. After a bit more research I suspect it is this propane/isobutane mix: https://eco-freeze.com/products/eco134/ (R436A or R436B are slightly different mixes of this 54:46 and 52:48)
It seems to be 20+% more efficient, very low GWP (3.16) and cheaper. With the only disadvantage being that it could catch fire if let out in the wrong mix and ignited.
Anyone got any experience of this? - it seems like this stuff is in fact rather a good replacement. Do people's engines catch fire in practice? It does seems like they really should come with a warning label to indicate that the system has been changed to HC gas and thus the fill volume has changed and there is now an explosion risk during maintenance.