Never said deca would suppress exo test.
One could take no test and 1g of deca a week too and some will be fine on that, others will suffer big time.
Many will be fine on half as much exo test as deca as well, but many others will not. The safe bet, if you dont know how you respond to deca is to take more test than deca.
Your asking for advice on a topic that varies greatly from person to person and looking for how its going to affect you but no one can tell you that. If you want to be a guinea pig and test no/low exo test with double the deca dose go for it and when your done let us know how it goes. Your experience wont necessarily apply to anyone else but Id still like to hear how you fare.
And on an aside, its not purely "bro knowledge" but empirical knowledge gained and followed by many HRT clinics.