Oh I bet you can ;)
I'm getting deeper in it :o Scientifically you are correct, and I'm sure it states in the instructions you must do xy&z. In my experience this is a way of covering themselves, and who can blame them. I can only say as I find, and if people choose to follow the rules I wouldn't frown or mock them for it, other than to say in my experience I have never had an issue with the way I install baths.
So you fit baths and do not realise properties of silicon functions best under compression and glass fibre deforms/flexes. Both being the reasons why the manufacturers and suppliers of these products (as linked above) advice contradicts your own. It hardly as if they could know more is it!
Oh dear I'm in trouble.... From my own personal experience I silicon all my baths to the wall resting on a battern, and never had one fail. I have even had to remove one months later as a new owner wanted to convert it to a shower tray in the end it involved an SDS to separate the two as it wasn't for moving.
Wickes,B&Q, plumbworld, bigbathroomshop and even unibond (sealant manufacturer) state to fill before application. (39) How to Seal a Bath with Wickes - YouTube (39) How to seal a bath - YouTube How to Seal a Bath Properly (plumbworld.co.uk) How to Seal Around the Bath (bigbathroomshop.co.uk) DIY Lesson 101: How to seal a bath (unibond.co.uk)