A granite fabricator should have the means to capture most of the dust, keeping it out of your cabinets, drawer sliders, and sock drawer.

Note that edge supported cooktops will need some structure passing across the area where the two cooktops meet capable of providing stiff support. Perhaps steel attached to the cabinet frame. Meet requirements for cooktop cooling.

Whether a hood is adequate depends not only on overlap, but flow rate and other details. Read hood and make-up air threads here, or provide details of what you actually have in place.

Adding or replacing gas will require non-combustible surfaces and potentially non-combustible wall construction, depending on the installation instructions. This is not a drill.

Just put a 24" Gaggenau gas or induction module, some other 24" gas top in the middle, maybe?

Regarding the vent, i haven't caught any stickers or tags, but there's 4 switches with 4 separate fans... they seem pretty stout.

i've found some 2nd-hand gaggenau gas cooktops that would match what i have here, but if i'm honest, i'm not a huge fan of the look. the kitchen/granite is relatively timeless, but IMHO the cooktop dates it pretty bad... i know they're very Euro looking, but i don't care for it.

i'll do some additional research on the induction before pulling the trigger.

Replace the radiant with the induction module. Done, Done, and Done.

"Is it feasible to cut the granite myself, or is it too risky and just hire a professional?"

This depends upon your level of skill, your tool selection, and your fussiness level. You aren't going to crack the stone.

I'd charge you $750.00, my minimum; there would be no mess.

Get a 30” and a 12” cooktop and have a black piece of granite cut to put inbetween the two tops.

If you are considering induction, look at the induction models in the 7000 series on the UK or German Miele websites. These are full surface options. They could be finally announced for the US at the spring KBIS show.

Definitely replace with induction.

thank you all for the comments. I will look into the induction, but i've got to be honest, i'm partial to gas... both aestetically and practically. However, i'll see if i can get a demo on an induction top to experience it for real

In relation to induction - - one of my hopes with the two cooktops was to utilize one of them with a very large griddle like the ones made by SteelMadeUSA ... i have fallen in love with cooking on my Blackstone, but with a long winter season in the north, i'd like to bring this inside. Would such an idea work with the induction?

If not, i suppose i could put a gas and an induction next to each other, and use the griddle on the gas top... and then i'd have both options available if i ever so chose... but i do have some concern that this would look goofy........ ?

There are induction griddles having large thermal mass for maintaining temperature when food is put on them yet having the power control to keep them finely regulated in temperature as well as get them to temperature in relatively short periods of time. Most of these are too heavy and large to move onto a counter for intermittent use, but should instead be built in if they can be fitted.

Sorry, but I didn't save any references when I looked at them a few months ago. Most are of French origin (search planche), or are from Cooktek.