Suppress annoying messages

advice-yatex-msg.el

(with-eval-after-load "yatex"
  (put 'YaTeX-insert-braces 'begend-guide 2)
  (defun advice:YaTeX-insert-begin-end (env region-mode)
    "Insert \\begin{mode-name} and \\end{mode-name}.
This works also for other defined begin/end tokens to define the structure."
    (setq YaTeX-current-completion-type 'begin)
    (let*((ccol (current-column)) beg beg2 exchange
	        (_arg region-mode)		;for old compatibility
	        (indent-column (+ ccol YaTeX-environment-indent))(_i 1) _func)
      (if (and region-mode (> (point) (mark)))
	        (progn (exchange-point-and-mark)
	               (setq exchange t
		                   ccol (current-column)
		                   indent-column (+ ccol YaTeX-environment-indent))))
      ;;VER2 (insert "\\begin{" env "}" (YaTeX-addin env))
      (setq beg (point))
      (YaTeX-insert-struc 'begin env)
      (setq beg2 (point))
      (insert "\n")
      (indent-to indent-column)
      (save-excursion
        ;;indent optional argument of \begin{env}, if any
        (while (> (point-beginning-of-line) beg)
	        (skip-chars-forward "\\s " (point-end-of-line))
	        (indent-to indent-column)
	        (forward-line -1)))
      (require 'yatexenv)
      (if region-mode
	        ;;if region-mode, indent all text in the region
	        (save-excursion
	          (if (fboundp (intern-soft (concat "YaTeX-enclose-" env)))
	              (funcall (intern-soft (concat "YaTeX-enclose-" env))
		                     (point) (mark))
	            (while (< (progn (forward-line 1) (point)) (mark))
	              (if (eolp) nil
		              (skip-chars-forward " \t\n")
		              (indent-to indent-column))))))
      (if region-mode (exchange-point-and-mark))
      (indent-to ccol)
      ;;VER2 (insert "\\end{" env "}\n")
      (YaTeX-insert-struc 'end env)
      (YaTeX-reindent ccol)
      (if region-mode
	        (progn
	          (insert "\n")
	          (or exchange (exchange-point-and-mark)))
        (goto-char beg2)
        (YaTeX-intelligent-newline nil)
        (YaTeX-indent-line))
      (YaTeX-package-auto-usepackage env 'env)
      (if YaTeX-current-position-register
	        (point-to-register YaTeX-current-position-register))))

  (advice-add 'YaTeX-insert-begin-end
              :override #'advice:YaTeX-insert-begin-end))