Erigon v.3.5.0 PruneSmallBatches not firing for 56+ hours during initial sync - mdbx growing unchecked

[ZekaPaun]

Version: v3.5.0-230b11a7
Chain: bor-mainnet
Mode: --prune.mode=minimal
batchSize: 1024m
db.pagesize: 16k (set at creation)

PruneSmallBatches last fired: Apr 2 01:41 UTC
Current time: Apr 4 09:45 UTC (~56 hours ago)

Steps cleared last time: 3728-3729
Current step: 3748
Backlog: 19 steps uncleared (3730-3748)

Applying steps running continuously (3730→3748 all completed/running)
Commit-time prune=4-15ms (essentially zero)
mdbx: 4409GB growing at ~6GB/hour
Limit: 5000GB → ~97 hours headroom

Is PruneSmallBatches supposed to fire during initial sync with prune.mode=minimal? Is there a condition blocking it?