Fitting avm manual hubs

hello everybody,
A good friend of mine ask me to try to search some info about fitting AVM manual free wheel hubs.
He has a 2017 S. Jimny. Few weeks ago he fitt AVM F.W.H. And 4x4 light start to flash. After reading of a thread about flashing of this light IFound that there is probably leakage of the vacuum through the manual hubs. Thats why the light is flashing, isn't it?
Could the fittment of theese manual hubs make some problems in future?
Is possible to stop flashing the 4x4 control light? For example block the tubes near hubs? Of switch off the sensor or so?
And the biggest question is:
When he drive with locked hubs on 2wd, so the whole front is rotating threw the locked hubs, could this lead to some damage in transfer case which should be normaly without movement during 2wd?
The reason why he wanted to fitt manual hubs was, when he tow a trailer especialy on reverse on non slippery surface to the corner up the hill, he wantet to drive with ruduction and save the difs. He uses the trailer very often and he has to reverse it back to home as I wrote above.
Is there anybody, who can help?

Sorry for my english.
I hope everything is understandable...
Thanks Filip

I understood you perfectly....then again my English isn't very good either. I'm an American.

Bosanek set up a very good guide in the wiki here:

Hub Conversion

Following his flow chart in the article your friend has done solution 1b. He needs to add either solution 2a or 2b. If you choose 2b, you will likely go to a final step with solution 3a. If you do this, Helijohn had a very good and simple (best of both worlds) version of the solution in his post here:

Stop the Flashing Light

Thank you very much!!!
It is unbeleveable comprehensive information, WOW!
All our questions are answered.
thanks again!

Greatings from Prague to America.