Helix 9 G2N Bottom Hardness ACL?

I got a new Helix 9 MSI G2N and just before our lakes locked up and I was trying to do a lot of mapping for ice fishing. I mapped a few small lakes before I figured out roughly how to dial in the settings for bottom hardness. I have a few questions:
1.If I didn’t have the hardness dialed in via ‘minimum hardness’ ‘maximum hardness’ and ‘gain’ can I go back and get it to display? I’ve monkeyed around with it in my living room but can’t get it to display any bottom hardness.
2. What is the best way to tune these 3 settings? I am getting nice color differentiation but probably not doing it exactly right, Where do you begin your adjustments on these 3 settings? Gain?
I have more ?’s but thought I’d start with these
Thanks!

I’m a little confused by the question about bottom. Mapping in GPS side and bottom hardness sonar side? Your mapping doesn’t relate to real time sonar readings.

I usually drive around at 6 mph with a split screen depth on the left and bottom hardness on the right. It will map and save depth and bottom hardness so I can go back later and use it. When I began mapping I didn’t understand that I needed to ‘tune’ my bottom hardness. My question is can I go back and tune the bottom settings to display information that I may have gotten while mapping the lakes (without having tuned my bottom hardness settings). Can I tune them after the fact or am I SOL?