The new code provides competent mechanics. Previously, the pen had strange reflections. The problem was in the 2D rendering of Unity itself: the glass shader did not work with "sprite-render" if the layer in the sprite was greater than 1.
Refraction works with new code.

The game is still in development support me :)
https://twitter.com/PAPERTANKS2
https://www.youtube.com/channel/UChy9stkBBtr9ZIakwD5Hwd
https://store.steampowered.com/app/1213020/PAPER_TANKS/