Mark, first I'm note that your experiments is very interesting for me.
The solution turned orange upon adding metaborate,
metaborate is alkali. orange color because phenidone oxidized by metaborate
and clear again upon adding ascorbic acid, and it fizzed upon adding the ascorbic acid, with visible foam.
ascorbic acid with metaborate produce sodium ascorbate, which recover oxidized phenidone.

I don't understand why you need to mix metaborate with phenidone/ascorbic acid. Try to make concentrate as follow
part A: glycol+phenidone+ascorbic acid
part B: water+metaborate+sulfite