installing an induction hob

Hi, I hope you can help me. I have been trying to get a definitive answer from Neff but keep just getting referred to their online drawing which is not what I want. My problem is I wish to replace my 20 year old Siemens ceramic hob which is 640mm wide with an induction hob – and my preference is for the Neff 800mm wide one T4383. However I am concerned about the requirements for space underneath the top of the worksurface.
Underneath the existing hob is a void space 180mm deep before you get to the top drawer. However as the new hob has to be wider than the old one there will be 8-10 cm of the appliance at either side over adjacent kitchen units – on the right being more drawers but with only 60mm before you hit the drawer and the same the other side before you are in the corner cupboard.
My BIG question is – is it possible to successfully fit the 800mm wide induction hob within this situation? the drawing I keep getting referred to shows two views one showing a minimum distance of 65mm between worksurface top and drawer underneath and then it shows another set up which has a smaller gap but gives no explanation. It also says that the distance is 30mm if above an oven.
Do you think that if the bulk of the induction hob is above the central void which is 180mm deep that the lesser space at either side will be ok?
I do not want to spend £700 on a new hob and then discover that I have to totally rip out my kitchen to install it.