This is a feature suggestion so feel free to completely bash it into the ground and let the crucible of the internet be the judge it is meant to be ;)
Steel Path Plus would be a mode open after you complete all nodes in Steel Path and it would change very little of the common steel path experience. The only change is that you get a dropdown or text field to choose the starting level of a node. Effectively making it possible to scale any node as high as your crazy build allows. As someone who already has all the snowglobes from completing Steel Path sometimes, just sometimes, I feel like trying something weird or see if a particular forma count is enough and if damage is scaling like I want on a build and making it possible to start any node from, let's say, 5000 would mean less waiting and more shooting.
This doesn't have to be as simple as that. This would be just the starting form of this. This mode could/should include:
1. Reward scales relatively so if you can consistently complete a lvl 9000 capture you get X times the reward, etc
2. After every X levels (100s or 1000s) the Steel Path Modifier could scale (the 200% extra heath and what not)
3. This could eventually become a Platinum Path, Diamond Path, Oxium Path with different modifiers
4. Eximus units could start to compound modifiers and a Blitz Frost guy could whip you into submission
5. Eximus modifiers could start getting additional painful features like a Frost actually freezing you for entering the bubble for the first time or a Leech becoming more and more powerful the more HP it leeches.
I completely understand this would only ever be visible for a small percentage of players buy it would inject new life for exactly those that dedicated enough to even need such a feature.