Based on Isaiah 55:8–9 (NASB), we can speculate about God's (the Father, Yahweh's) morality and why He allows suffering, but we cannot convict Him of absolute immorality.
Isaiah 55:8–9 (NASB):
“For My thoughts are not your thoughts, nor are your ways My ways,” declares the LORD. “For as the heavens are higher than the earth, so are My ways higher than your ways and My thoughts than your thoughts.”
We can investigate the Problem of Evil, evaluate proposed explanations for suffering, and speculate on God's moral purposes and plans. But within the biblical framework, His thoughts and ways transcend our own in ways we cannot fully understand. Therefore, we must consider whether we possess sufficient knowledge and capacity to pass absolute moral judgement on Him.
That does not mean moral enquiry is invalid or that we cannot evaluate Him through the moral frameworks available to us. Rather, it means we should distinguish between moral evaluation and absolute conviction. We can question, investigate, and reason about God's morality without claiming to comprehend the full scope of His purposes and plans.
Therefore, based on Isaiah 55:8–9, I believe we can reasonably speculate on God's morality and the reasons He permits suffering, but we cannot justifiably convict Him of absolute immorality when our understanding of Him remains limited by the constraints of our own ontology.