I own an inspiration (ce) and a sidekick (non-ce). I dive both here in Europe.
If you teach as instructor, you must be on a CE unit. The students can be on a none-CE unit. This are the rules. Nothing more, nothing less.
For insurance it does not matter, diving is a private thing, and there is not stated in my insurances the word CE. So if something happens and I was diving the Sidekick, or homebuild, I am unsuranced by DAN and by my travelinsurance.
Both my insurances don't state that I need to have a cert, or that I have to dive within certification limits. Nor don't they state that my equipment must be proven in good condition, some state this, and I do all the servicing myself, but am not an official dealer (there is where the problems start, I had bad experiences by letting regulators serviced by an official dealer).
So the student has his own insurance and the instructor has his insurance for both an accident with his own healt, and for the case people think he did something wrong. But as long as you are on a CE unit, there is no problem. This means that sometimes agency standards and laws are different, but then the agency will accept the laws.
The same is here in my country with the personal data, agencies sometimes require you save them for 7 years, but the law states that we are not allowed to save data longer than needed. This can give conflicting things.
In my country, Netherlands, diving does not have any rules or law. This means everybody can dive, buy equipment, etc without any course. If something happens, it is all paid by the by law required national health insurance. If you go abroad, all is paid till the national level o the national health insurance. If you go to countries where it is more, a travelinsurance has been adviced. Also the national health insurance don't pay for things like a search, or transport from a difficult place. This means for everybody a travel insurance has been adviced. And a travel insurance can have different rules. Some state no technical diving, others state diving within certification limits, some state diving with equipment where the quality has been proven, etc. But some travel insurances don't state anything and then you don't have any problem. My travelinsurance does not state anything about certs, depthlimits, equipment, gases used, etc. But cave diving is excluded. For cave diving I have my instructor DAN insurance.
And sometimes insurances bounce with certification rules. My CMAS 3* cert is a 60m on air cert. Sometimes there are PN2's mentioned in an insurance. But if I just use my 60m on air cert, I don't do anything outside a certification limit.
So if you just buy a JJ in parts, you don't have to worry. Also if you dive a homebuild CCR, you don't have to worry. And if you are worried, you can buy CE-stickers in China and stick them on your unit. I have also done for fun on my sidekick
Further, remember that replacing a hose on a regulator also means you changed things and that there is theoretically no CE anymore. So no single LONG-HOSE configuration has theoretically CE. And nobody cares, even no single insurance. Also 1 brand of first stage and another brand of second stage is theoretically no CE anymore, but no insurance will make a problem of this. The second stage only needs to get some gas within intermediate pressure limits, and doesn't know which first stage delivers it. So also here, don't worry.
My Inspiration is putted in an ali box and that is ok. The unit itself is not modified further, so original computer, loop, lungs, scrubber, first stages. So it is completely CE. The box doesn't matter, as this is just a case to protect it, otherwise this means I never can replace any box as even the original brand has changed the yellow box since I bought mines, and with the older batterypack, this is for sure not tested
There will also nothing happen as you get an accident or something. Don't be afraid. If you dive a Halcyon backplate and a DTD wing, don't worry, this combination is no problem.
My unit has CE without M26 valves as this was at the time of building ok. Now people buy the unit with M26 valves and order the normal valves and then replace them directly. In my country, I don't know any diveshop that requires M26 valves. I only know that some cannot fill M26 as they don't have an adapter for it. In Germany I always get my cylinders filled without M26 valve.
The only thing I have heard is that in France some people have been refused on boats with a none-CE unit. But a modified unit was no problem. So the JJ in gue configuration is no problem, but a Sidekick is.
This is also the reason that nobody complaigns if a gue JJ course is teached in Europe with the instructor diving the gue configuration. But officially you are not allowed to teach a Sidekick course while diving on a Sidekick as instructor.
