No, it did have 20mm cannons,
I think this mod already comes with 20mm cannons .... therefore a good job well done IMHO.
but 30mm cannons were considered.
No, this is incorrect, in their book on the He 280 Colin Heaton and Anne-Marie Lewis
speculate:
Equipped with three 30mm cannon and capable of 512 miles per hour, the He 280 would have provided a bridge between the Fw 190 and Me 262 and would have enabled the Luftwaffe to maintain superiority in Europe at a time when the Allies had no comparable aircraft.
Any "fantasy-waffe" change would therefore be a "request" .. and there is a thread for that IIRC
We are reaching a point where any mod that is put out these days is met by someone saying "It is ok, but I want.... this.. or that ...or more .. or bigger .... etc ... etc"
G;