I was referring to the lees ageing process that traditional champagne goes through . Bottles are left on their sides for a long period , sometimes ten years before disgorging.
This is to let the bottle fermentation stage dead yeast lees have an increased surface area ( increasing contact with the wine and reducing the chance of reductive h2s from forming in the bottle , thinner lees layer , less chance of reduction) and so that as the yeast age and start to decompose , this is known as autolysis
Autolysis refers to the enzymatic self-destruction of yeast cells. The most important aspect of autolysis for sparkling wine is the release of flavour components: e.g. benzaldehyde (nutty, toasty), cis- & trans-farnesol (sunflower) & amino acids, proteins and lipids that act as surfactants. This gives the sparking wine it's nutty and creamy notes , it also triggers the sweetness sensors of our pallet making the wine taste sweeter than it really is , buffering the sharper acidity that most champagne style wines have , this is mort critical with dry styles .
Autolysis is affected by
Percentage alcohol: increases speed of autolysis
pH: higher pH favours quicker autolysis
Temperature: higher temps cause increased speed, but interfere with natural ageing, so optimum is 10 - 15°C
Time: there is very little autolysis for first few months after alcholic fermentation, with the most significant increase in next six months. e.g., wine is 24 % higher in amino acids after 1 year & 30 % after 4 years. After 6- 8 years, there is no further autolytic activity.
By using an inactivated yeast product , you are " faking it" by not needing 6 years of lees contact because these autolosys amino acids , peptides and proteins are already in a free form in the inactivated yeast product and react fairly quickly 1-3 months with the wine , so you get most but not all of the benefits of an extended lees contact ageing without the multi year wait.
Optiwhite or any of these products will have a similar effect .
I would think optiwhite or booster blanc the primary ferment to improve mouthfeel and promote yeast health would be a good idea , this would help ward off h2s .
During carboy aging would be the time to add biolees or noblesse , an addition at the top end of the manufacturers recommendation , stirred up once a month gently and ageing in the carboy for 3 or 4 months before bottling would give the wine a good base of yeast character . You will want the wines own fine lees as well as these siy products in the carboy during the ageing .
Even after you filter going into the bottle these siy residues will promote yeast health for the secondary ferment .
If you are going to use gum Arabic , use a pre filtered brand like Keller or arabanol and add it to your carboy a week or two before filtering and bottling stage.