From ROMANS 9 (R9) SIMPLY EXPLAINED by Jacques More
R9:22-23
What if God, wanting to show His wrath and to make His power known, endured with much longsuffering the vessels of wrath prepared for destruction, and that He might make known the riches of His glory on the vessels of mercy, which He had prepared beforehand for glory,
We are missing central and vital truth here in translation. A sentence makes a complete statement. This is always accomplished by the central use of the verb describing the action involved. Two verbs are here in 22-23. They are each connected to one or the other of the two different subjects: the vessels of wrath and the vessels of mercy. What is missing in translation is that they are not the same verbs. The vessels of wrath come first and these are “prepared” or “fitted”. The vessels of mercy are mentioned second and these are “afore prepared”.
“Afore prepared” is all one verb and is only used of the vessels of mercy; “prepared” or “fitted” is a different verb and is only used of the vessels of wrath.
The difference in these two verbs involves time. It is readily seen in “afore prepared” since being prepared in advance means ahead of the present. In contrast being “prepared” or “fitted” we can see involves much time in the lifetime of the person with the words added showing this well, where God is seen to endure “with much longsuffering”. This is not action before the lifetime of a person but during their lifetime.
God is Open 
Great post Christopher!
The BDAG also describes these two very different words differently.
– κατηρτισμένα (Romans 9:22) “Designed for destruction”
– προητοίμασεν (Romans 9:23) has the prefix “Pro” (which means in advance)
Described in the BDAG as “Prepared as a Goal”
We can note that neither of these words require determinism.
κατηρτισμένα (Romans 9:22) – can easily be seen as Paul referencing his previous statement in this letter: “as by Adam sin entered into the world”
προητοίμασεν (Romans 9:23) does not require determinism either.
To state that someone has a target described as a “Goal” – is to affirm that that target or Goal may not be met.
If anything – προητοίμασεν infers an IN-deterministic meaning rather than a deterministic one.
Blessings! :-]