Steaming or boiling is done - why?
To make the egg albumin harden to give bait a skin to stop nuisance fish and aid casting. To bind the bait together.
How long do you boil an egg? There is one answer.
Steaming - lose less of the attractants V boiling. Boilie recipes are designed for boiling, not steaming and designed to compensate for loss of flavour in the boiling process. So if you steam baits (about 5 mins for 20mm boilie) you need to factor that into your rolling process and adjust recipe, under flavoured definitely best.
Carp work on chemo-reception but have taste buds in their mouth which are unique (different to those on their body), can taste sweet V sour for example. But more likely to be initially attracted to bait via chemo-reception coming from base mix + protein + vitamins/minerals + amino acids etc..., not how the bait tastes (taste from solubles) - but that might affect how long they hold it in their mouth, up to 15 secs if they like it or just a few secs if its too strong (repellent).
Bit complex to explain briefly - but I always steam - but if I use a bought 'flavour' I would only use 2.5ml per egg, not 5ml. Can make up the other 2.5 ml with soluble oil, such as hemp oil for example, if high leakage type bait preferred.
Will break down faster in water if steamed not boiled - correct. Not always a bad thing though
As always, do your research, adapt things a bit, but firstly understand why you are doing something and have an idea of how you are going to apply it at the lake. Bait is one part of it, steaming might give you an edge if you use your head though and have a plan to start with. Like most things in fishing, rigs particularly, they are designed initially for a purpose and when used incorrectly they do not always help, in fact may often hinder.