在背景层上设置的选项的范围规则是什么（使用背景包）？

Question

如下图所示，一些选项似乎不受其范围的限制（例如，线条粗细和虚线），而其他选项则受到限制。（使用包backgrounds。）规则是什么？另外，请注意箭头大小的奇怪后果。

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{backgrounds}
\begin{document}

\begin{tikzpicture}[x=1in,y=1in]
\draw[ultra thick,blue] (0,1) -- (2,1);
\begin{scope}[on background layer]
\draw (0,2) -- (2,0);
\end{scope}
\begin{scope}[on background layer={ultra thick,red,dashed,->,>=latex}]
\draw (0,0) -- (2,2);
\end{scope}
\end{tikzpicture}
%
\begin{tikzpicture}[x=1in,y=1in]
\draw[ultra thick,blue] (0,1) -- (2,1);
\begin{scope}[on background layer={red,dashed,ultra thick}]
\draw (0,0) -- (2,2);
\end{scope}
\begin{scope}[on background layer={->,>=latex}]
\draw (0,2) -- (2,0);
\end{scope}
\end{tikzpicture} 
\end{document} 

Answer 1

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{backgrounds}
\begin{document}
    
    \begin{tikzpicture}[x=1in,y=1in]
        \draw[ultra thick,blue] (0,1) -- (2,1);
        \begin{scope}[on background layer]
            \draw (0,2) -- (2,0);
        \end{scope}
        \begin{scope}[on background layer={ultra thick,red,dashed,->,>=latex}]
            \draw (0,0) -- (2,2);
        \end{scope}
    \end{tikzpicture}
    %
    \begin{tikzpicture}[x=1in,y=1in]
        \draw[ultra thick,blue] (0,1) -- (2,1);
        \begin{scope}[on background layer={red,dashed,ultra thick}]
            \draw (0,0) -- (2,2);
        \end{scope}
        \begin{scope}[on background layer={ultra thick,dashed,->,>=latex}]
            \draw (0,2) -- (2,0);
        \end{scope}
    \end{tikzpicture} 
\end{document}