Noseweight advice

I tow a 2013 Coachman Pastiche 560/4 with a MTPLM of 1630kgs. I've recently changed my towcar from a Hyundai Santa Fe (Kerbweight 1977kgs and max noseweight 100kgs) to a Skoda Kodiaq Edition 4x4 (Kerbweight 1798kgs and max noseweight 80kgs). Considering the Kodiaq is the current towcar of the year I have been very disappointed with the towing stability of my outfit and despite careful loading and checking of tyre pressures I've had a few episodes of snaking (between 50 and 60 mph in the absence of strong winds), including one event where the car's towing stability assist activated the ABS to bring it under control. The caravan is fitted with ATC and an Al-Ko stabiliser hitch.

I purchased a noseweight gauge and found that the noseweight of my Coachman when totally emptied for winter (apart from two standard gas bottles in the front locker) was over 100kgs.

Please can anyone offer advice, firstly on whether I'm expecting too much of my towcar at a 90% match (bearing in mind I have 30 years towing experience) and secondly whether it's normal to have to remove gas bottles and add "ballast" behind the axle of an empty caravan to reduce the noseweight to an acceptable level. If I remove the gas bottles from the front locker, where is the safest place to carry them?

Thanks in advance to anyone with useful advice.