issue with custom preamble for math preview

[nicolaslesquoy]

Hello, I want to use with the math preview feature the following macros that use in almost all my documents :

\begingroup
    \def\tmpa#1{%
        \if\relax#1 \expandafter\noexpand \else
            \expandafter\gdef\csname double#1\endcsname{\mathbb #1} %
            \expandafter\gdef\csname script#1\endcsname{\mathcal #1} %
			\expandafter\gdef\csname frak#1\endcsname{\mathfrak #1} %
            \expandafter\gdef\csname cal#1\endcsname{\mathscr #1} %
        \fi \tmpa
    }
    \tmpa ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\relax
\endgroup

I wrote it in the LaTeXTools.sublime-settings file as :

// An array of the used packages, from which the file for the live preview
	// will be generated.
	// Just write \\usepackage{packagename} to include other packages.
	// (The xcolor package will be present, even if not in this list.)
	"preview_math_template_packages": [
		"\\usepackage{amsmath}",
		"\\usepackage{amssymb}",
		"\\IfFileExists{mathrsfs.sty}{\\usepackage{mathrsfs}}{}",
		"\\IfFileExists{mathtools.sty}{\\usepackage{mathtools}}{}",
		"\\IfFileExists{esvect.sty}{\\usepackage[g]{esvect}}{}",
		"\\IfFileExists{latexsym.sty}{\\usepackage{latexsym}}{}",
		"\\IfFileExists{mathtools.sty}{\\usepackage{mathtools}}{}"
	],

	// An string of the remaining preamble (not packages) for the file,
	// which generates the math live preview.
	// Can also be an array, with an string for each line (as in the packages).
	// For technical reasons DON'T include other files.
	"preview_math_template_preamble": [
		"\\begingroup\\def\\tpmab#1{\\if\\relax#1\\expandafter\\noexpand\\else\\expandafter\\gdef\\csname double#1\\endcsname{\\mathbb #1}}\\tmpab ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\\relax\\endgroup",
		"\\begingroup\\def\\tpmac#1{\\if\\relax#1\\expandafter\\noexpand\\else\\expandafter\\gdef\\csname script#1\\endcsname{\\mathcal #1}}\\tmpac ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\\relax\\endgroup",
		"\\begingroup\\def\\tpmaf#1{\\if\\relax#1\\expandafter\\noexpand\\else\\expandafter\\gdef\\csname frak#1\\endcsname{\\mathfrak #1}}\\tmpaf ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\\relax\\endgroup",
		"\\begingroup\\def\\tpmasc#1{\\if\\relax#1\\expandafter\\noexpand\\else\\expandafter\\gdef\\csname cal#1\\endcsname{\\mathscr #1}}\\tmpasc ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\\relax\\endgroup",
	],

Those modifications are not used when I type in a math environnement for instance \scriptC instead of mathcal{C}.
Thank you in advance for any advice.