I honestly don't see why that code would cause issues, but you can certainly try using different hooks. Here's a list of the hooks used in order around where parse_templates is used (you could get this in debug mode on your test site). Try some other and see what happens.
Code:
fetch_foruminfo
load_show_variables
load_forum_show_variables
global_state_check
global_bootstrap_complete
global_start
style_fetch
global_setup_complete
forumdisplay_start
cache_templates
cache_templates_process
template_register_var
template_render_output
fetch_template_start
fetch_template_complete
fb_opengraph_array
parse_templates
notices_check_start
friendlyurl_clean_fragment
friendlyurl_geturl
notifications_list
process_templates_complete
friendlyurl_redirect_canonical
cache_ordered_forums