What is puzzling me is that miners, I thought, are dormant in winter. If so, your first post was about damage in the autumn? Or are they eating away now? The damage and life cycle sound similar to leek moth but for sure, moths have pupated three months ago and hibernate as dormant moths I believe, in obscure places, not in the soil.
At least I have found that my leeks which were three quarters (by number) damaged last summer and until September, have recovered really well with plenty of healthy growth in late autumn, even a little now. The damaged leaves and stem are still apparent when they are trimmed for eating, but with lots of tasty new stem underneath.
IF the miner damage is historical, your leeks can still grow more, until late April in fact, before flowering time arrives.