How are you doing surface mapping now? Don't forget, the majority of players will only map a surface if the initial scan from the DS shows there is something on the planet, and the will be systems that don't have any POI at all.
Now I just drive on the planets surface (or fly above) and search for interesting things, that can be time consuming, driving around in hope of finding some canisters full of gold, crashed satellite or a ship wreck
But using probes seems more fun and I'd like to do that too but I will be unable to because I don't have the slot for the new module. I'm not talking about deep space exploration, I would use my exploration ship for that and I have room for those modules. I'm talking about doing some missions, then making detours to investigate some random planet POI and for that I'd like to fit the probe launching thing to my multipurpose ship that I use almost exclusively. But I can't, there is no more room, nothing left that I can do without.
Some large ships would have enough compartments for everything I need but they have one major flaw:
no landing on outposts. And I just love outposts!
If only there was a way to be able to park your ship outside of the outpost and dock using your SLF... how happy that would make me!

But that's another topic.