[Typo3-dev] Using TS to config tslib_feUserAuth ?

[Stefan Geith]

Hi Devs,

I needed FE-User autologin, so have written the extension
'sg_feautologin' by extending tslib_feUserAuth
     class ux_tslib_feUserAuth extends tslib_feUserAuth {
     ...
         function start() {
         ...
         }
     }

Now I would like to make it configurable and
I defined some TS-Config-Data in setup:
     plugin.ux_sgfeautologin = USER
     plugin.ux_sgfeautologin {
         mode = 1
         test = 2
     }

But reading this with
     $this->conf = $GLOBALS['TSFE']->tmpl->setup['plugin.']['ux_sgfeautologin.'];
didn't work.
Seems, that $GLOBALS['TSFE']->tmpl->setup ist not defined,
when tslib_feUserAuth->start ist called.

Question:
Should I / Can I / How can I: read/create $GLOBALS['TSFE']->tmpl->setup ?
Or ist there another (in this case better) way to get some configuration-data ?
Mabe by using variables in localconf.php like $TYPO3_CONF_VARS["MyExt"]["mode"]=1; ?

Any Ideas ? Thanks !

Stefan