Don't worry Andy. Elite wouldn't print something on their packaging that was a 'crock of S**t'. The cycling magazines and press would pick up on it and give it a not-so-good review pointing out the charts are 30 % out from testing with a PowerTap.
If that happened, Elite sales would plummet, and they wouldn't want that.
You have to trust Elite's quality control dept to ensure the factory produces something that is +/- 5% at most of the marketing claims, or else they might fall foul of The Trades Description Act.
The 'road load' curve is a rudimentary way of expressing how much power is required to move a rolling vehicle. It's so rudimentary, it is in the very first module of City & Guilds 'Mathematical modelling the motion of objects', which I did during my YTS placement at MacLaren Pushchairs in the seventies.
The turbo trainer has a flywheel and a method of applying load to the roller. The flywheel simulates the inertia of the vehicle. The load increases as speed increases to simulate wind resistance and tyre deformation of the bicycle. It doesn't matter what bike you put on the turbo, its going to have a racebike windage because that's what the turbo's flywheel and load device is simulating. What the turbo doesn't simulate is the bicycle's transmission losses, which is the friction of chain links and its meshing with sprockets; and the rear wheel, pedal & BB bearings.
Correct tyre inflation and tyre pressure on the roller is important too. Read the instruction manual.

Don't worry either about being 40 Andy. I'm 53 and still turning <25 minute tens.