is it dangerous to change sql safe_characters ?

[d tbsky]

hi:
   we are using freeradius 3.0.9. and we want to make the sql
accounting data easier to read/process.
currently the characters below we may use are escaped by default

 '\'   => for windows account like "domain\user".
"+","=" => for base64 encoding these two characters are used

 is it safe the add these characters to query.conf "safe_characters"?

PS: by default the method to escap the "\" character seems not
correct. when user use "domain\user" to login, if I check with
"radiusd -X", the name sometimes present as 'domain\user', and
sometimes present as "domain\\user". but finally when it write to sql,
it becomes "domain=5C=5Cuser".
I think the correct escaped string should be "domain=5Cuser" ?

thanks a lot for help!!

Regards,
tbskyd