Your icons look great as they are shown here, large and with white background. But you have to consider in reality they are shown much smaller, size differs depending on screen size/resolution and also on the tab, they get blurred, and the background colour mostly will be different. The black rims around coloured elements in the present icons don't give a neat look, but help keeping them readable under these circumstances.
Dashed lines especially tend to look very blurry when rendered small. Also I think elements not saying really something, just added for looking good, should be avoided.
Using a dark variant of the chosen icon colour instead of black I find an interesting approach worth to be explored further. This dampens the harsh contrast but still helps readability.
When former developer ravas made the advanced more configurable user interface, he incorporated a possibility to change the icon colour to your likening. I have never tried to find out how this works and experiment with it. But the use of this feature should be in the mind also.
Thanks for the improvements to the icon set! I would like to suggest another change to the snap icons.
The current version of snap center and middle represent the same line and circle, and the very subtle difference is only the position of one green dot. When the two green dots are close, it is middle, when the two dots are far, it is center. I find this confusing and because there is no mnemonic that can be associated to that, I need to observe both and think for a whole second before I can tell which icon to click.
I would suggest to keep only the curved line for center, and the straight line for middle. See the image top row is the current version, the bottom row is a modified version (just a bitmap screenshot edit), with fewer but more clear visual clues.
I believe the original version intended to cover edge cases where straight lines have a "center", and circles a "middle", but I think the ability to identify which is which at first glance, and therefore create a mnemonic, is more important than including all the edge cases in a single icon.