offtopic:
A fill in for if would be
cond
1 1 =
start
blablabla
stop
remember that everything is in reverse polish notation.
I get where you are going with xnor. Three points:
1.) No one uses xor in the first place.
2.) You can always use 'xor not' (bot you probably already knew that)
3.) The last and only time I upgraded the DNA logic (breaking forward compatibility pretty well) was back in early 2013 when I introduced chloroplasts. Xnor was not on my list

(I really want to avoid doing that until the release of DB3) sorry.
Fun fact, DB3 will have even less shorthand commands then DB2, 'addstore' and all that other stuff will be gone and be replaced with codules.
Also, please try to stay on topic or post a question in Newbee...
Thx.