SMP vs FUE for scar repair?

[varonil]

I'd like to ask the brothers out there with experience on this forum for advice on the best scar reduction techniques for my situation.

I am on a multi year journey to reduce / hopefully eliminate my hair transplant strip scar in order to shave my head down to a 1 or 0. I've had 3 successful FUE into scar procedures with Dr. Robert Jones, that has greatly reduced my scar, the last of these being a few years ago - see the photo albums in my profile. While the improvement has been vast, the scar is still quite visible at a 1 or 0 shaver setting.

It sees that I got diminishing results with the subsequent FUE into scar sessions. My best guess at noticeable improvement to the scar 6 months after each session was:
1st op: 50% improvement
2d op: 20 % additional improvement
3rd op: 5% additional improvement.

I'm not sure if my case of diminishing returns is to be expected, or not.

I would like to have further work done, and am not sure whether to go or a fourth FUE into scar session, or whether to try scalp micro pigmentation (SMP).

Anyone have any thoughts on which way to go first?