We are taught that in "type 0" and "type 1" conditional sentences, the tense of the condition clause (aka the "if" clause) should always be the normal present tense, as in:
"Type 0" conditional: If you heat ice, it melts.
"Type 1" conditional: If he wins the lottery, he will spend it all on charity.
As with any other verb, when using the verb be in this position, its inflectional form must agree with its subject, as in:
- If he is smart, he will pass the tests.
However, is in the aforementioned sentence implies if the person is smart in general, not in one specific situation.
Does this distinction matter in English? If the latter were to be the case, meaning in a specific instance not something stated as a general truth, would it then be possible to use the pattern "If I be ...." instead of "If I am ...."?
For example:
Son: Please buy me a bicycle, Dad.
Dad: I will, but only if you be a good boy. [rather than "if you are ...."]
Does anyone ever speak or write that way today? If so, in what spoken or written contexts? If not, then have they ever once customarily done so at any other time or place than here and now?

