Much appreciated! Glad you retained it
POST addition: found this, MAX_VLANS, tried it ...
fgrep -r MAX_VLAN target/linux/ipq40xx/* | fgrep define
target/linux/ipq40xx/files/drivers/net/ethernet/qualcomm/essedma/edma.h:#define EDMA_MAX_VLAN_SUPPORTED EDMA_MAX_PORTID_SUPPORTED
target/linux/ipq40xx/files/drivers/net/phy/ar40xx.h:#define AR40XX_MAX_VLANS 128
So 128!