Boiler plume extension under balcony

[slap-bass]

I recently moved to a house that has a Worcester Bosch Greenstar 24 Ri ErP condensing boiler. It has the standard terminal outlet (part 87161112090):

https://www.plumbcenter.co.uk/product/worcester-bosch-87161112090-terminal-outlet/

The outlet is located underneath a balcony so I was thinking it might be better to extend it so that the waste gases are discharged away from the balcony rather than underneath it.

Would the 1 metre plume extension kit (part 7716191087) be the correct part to use:

https://www.tdlonline.co.uk/Heating...ter-Bosch-Plume-1Metre-Extension---7716191087

If so, would it be a case of simply sliding the plume extension over the terminal outlet and then securing it with the supplied bracket? I cannot tell from any of the photographs online if the plume extension is designed to click into place on the terminal outlet. I have read in a few places that silicone sealant should be used to improve the seal -- is that correct?

Thanks very much for any help you can provide.

 

[John D v2.0]

Being honest I think the tricky part would be checking the combustion gas concentrations and pressures afterwards, after modifying the flue system it all has to be checked out for proper operation.