i Don't know why, but your mod change the wagon colision box
all my bp are on "wagon bugger design"
and with your mod enable,i can't use it :/

https://pastebin.com/0XYgms8R
(with you mod i can't place white insert and pole betwen wagon)

idea, if we are on "up" side of cliff you can jump it (for low dommage structure)

Unfortunately, this is not a bug but how the mod works.

My mod adds the collision layer to all entities in that blueprint except the lamps and belts. So they are now on the same collision layer as trains. That is how I enable my hovercrafts to collide with the entities in the game. There is no better way I know of to enable the hovercraft to function as it does with out causing other more concerning issues and conflicts. Therefore there isn't much I can do to resolve your issue.

I am sorry and hope you can find a way to continue to enjoy my mod.

could you reduce this colision zone to be close at vannila ?

I am sorry, but it is not the size of the collision box that is changed. It is the collision layers that are changed. By default the only entities that have the train collision layer are trains, wagons, ect. However, I add the train-layer collision mask to most entities to enable my hovercrafts to collide with said entities. That change is what is causing your problems and unfortunately there is nothing I can really do about it with out rewriting the whole script and that would cause way more problems.

The mod used to work that way, but do to all the major issues and conflicts it was causing I changed how it functions to improve compatibility. So unfortunately the only options you have would be to disable/uninstall my mod or change your blueprint design. I would imagine disabling my mod would be the easiest as your blueprints are pretty unique. Thanks for using it and I am sorry it has caused such problems as it has for you.

"this is not a bug but how the mod works."
Your mod, modifies functions of the vanilla game and creates incompatibilities with the vanilla game, this is exactly the definition of a bug.

if the wagon have collision layer, just don't add layer to wagon, (or don't add layer 2time)
i'm pretty sure your can fix that.

It's an intended bug, feature, change, ect.

I should not adding the train-layer a second time to any entity. I should only be adding the train-layer collision mask to the other entities. I should have all entities that have the train-layer by default black listed from my mod's function of adding the train-layer collision mask.

I'm not trying to be rude, but as far as I know there is no way to fix your issue with out changing how my mod functions which sadly would only cause more problems then just the one issue you've run into. That is why I made the change I did with how hovercraft collision is handled compared to the original mod. Even the Wube devs complained about how that mod was handling the hovercraft collision/hovering. I honestly wish there was something I could do for you because I want you to be able to enjoy my mod; however, as far as I know there isn't. I am open to suggestion and very much appreciate your input.

your mod are fun,
thanks you