When should a BN let out his fryÉ

How soon should a male ABN let out his fry?
I have three escapees and they have used up most if not all of their eggs sacs and now are seeming to be latched onto the zuchinni.
Was wondering if I should lift up papa plecos cave and let the remaining fry out?
I know he has a clutch if not two with him.
He tends to hold onto his fry. His first three batches one day just appeared and they were 1cm long and quite big, so I think he was hiding/protecting them, but they were weak and over 99% died over the next few weeks. Out of over 70 fry I was left with 4. Not very good.
This 2nd last batch he kicked-for whatever reason and I artificially raised them and out of 15 fry I still have 14 and they are larger than their 2+ month old siblings.
So what do you think I should do-leave him alone and let him release his fry when ready or should I do it for him
There are 7 cories with the BN in that tank.

It all depends on the individual male and the type of cave on how soon the fry emerge. Once the fry start moving around it becomes harder for the male to keep them in the cave. Just leave him to it they may come out in dribs and drabs or he may just let them out on mass.

When the fry emerged in the past what was your normal feeding and water change routines for them.

My first few batches of fry were fed zuchinni (maybe too much) as it really polluted the tank water and it is likely the cause of the mass dieoffs. I learned from that mistake.
I would put pieces of zuchinni in a veggie clip and they ate okay for a while and then they slowly stopped-may have been the water or maybe they couldn't find the food as quickly as they needed as they were all over my twenty gallon long.
My 2nd last batch have been raised in a plastic floating breeder box with 4 time daily water changes and new zuchinni everyday or whenever they finish off the last pieces.
This batch has had total fish owner support as they were kicked and would have been lunch for my cories- lucky water-change and the eggs were found.

best bet is to leave the timing of fry release to dad.

when it comes to food fresh veges are the best for the young ones. though change them over on a regular basis, particually the zucchini as it will pollute the tank badly!

Agree with Doug, leave it up to dad.

The strong will survive and the weak will die. Crual, but that is the way nature works.

All you could do is monitor the quality of the water, and leave the cuc, etc. only during the course of the night.

Papa pleco either let his fry out today or some decided to go explore alone. I have at least 4 that were in the main tank and a few I saw were deciding if they wanted out or if they wanted to stay with Papa a little longer. Those long whiskers are a good defense and the young are very defenseless. Thou my cories seem like they could care less. Thanks for all the help.

You will find that they go back in also cute little things...Congrats