Knock happens, but just because it does doesn't necessarily indicate anything bad. Maximum torque is located at the knock threshold, and occasionally we bump into it. Back before fuel injection made fuel delivery so much more precise, it wasn't uncommon to be driving next to a car that was pinging the entire time, so don't be worried about seeing the occasional blip because that's what the system is designed to see and protect us against. Definitely step up your tune and see how it goes as you're giving up a ton of timing with the 91 tune.
When it becomes a concern is when it's happening repeatedly or is resulting in high negative corrections-especially in the upper-rpm range. If you were running into either of those scenario's then it would be advisable to run a lower-rated tune. Neither of those appear to be the case here, so I wouldn't worry. I would note that you should probably ramp-into boost at that low of an rpm, and that punching it that hard, that low, could have been the main cause in that scenario.
If cyl 1 is a repeat offender, your first step is to pull your plugs and verify or re-gap them, and if they all check out then swap them around to see if the problem still exists in the cylinder or if it follows the plug. There's always the possibility that it is just temperamental, and if so there generally isn't much that can be done if a plug-swap doesn't take care of it. I haven't really seen those types of issues on the FiST though, but it doesn't mean that they don't exist-maybe the trend hasn't been established.
Your log list seems like an odd combo, btw.