Had a very similar situation here.
First screen they arrived with had No rain sensor despite me advising them existing had.They then tried to get out of replacing "like for like" as mine has the more expensive heat reflective treatment and they told me as it was a German factor order they would just fit the std no heat reflective screen.
I promptly reminded them I was the customer..the insurance were footing the bill(less my excess) so to get the screen correct for my car.
7 days later 2 guys arrived with the screen and promptly moaned form start to finish how difficult it was to fit and how heavy the screen was....tough!!!.When I told the guy who seemed to be the "senior fitter " he promptly appeared with a rubber mallet and started bashing them into the trim.I did say they wouldnt stay in place but he said that is how they always do them
and carried on.
The following day we were off on holiday and half way along the M4 the entire sscreen trim let go and disappeared into the distance never to be seen again ,so as the screen was water tight waitied till we returned 12 days later and contacted Auto Shite again.
This time the nicest guy you could possible met arrived the following day.Promptly advised he had fitted lots of Omega screens over the years and had to refit almost the same number after fitters who didnt know what they were doing had tried.Entire screen was removed again and fitted correctly with the trims and fittings in place and for the past 2 years have had no further issues.
Its all down to the guy fitting it tbh...all omega screens are the same with the exception of having/not having rain sensitive section.All have a shade band of varying colours and the heat reflective screen was a very expensive factory option.
Bets of luck and insist on getting a fitter who knows how to fit them properly and ensure he brings the full fitting kit including all trims and you should be fine