I'm late to this party.
You can add inserts on any input channel you wish, before it is recorded.
I think it's always a best practice to do it afterward, but you can add any effect you want on the Input channels in the Mix Panel.
If you ever do too much, there is no turning back, but you can do whatever you wish, with the Studio 68 or any other interface you choose. Studio One has supported that at least since V2, but I highly recommend you update to V3 when you can.
I had v2 Producer, and v3 is such a great workflow improvement, it's worth it. (Wait for the sales if you must... move as soon as you can!)