Replacing raw egg with gellan gum F in Choc Biscuit Cake

Prince William's Grooms Cake recipe contains 1 raw egg that I assume is for emulsification only in this refrigerator cake. Skipping it would not impact enjoyment (have done) but would replacing with 1/4tsp gellan gum F and 45g liquid improve texture (silkiness) over nothing at all?

4 ounces dark chocolate.(for the cake)
4 ounces granulated sugar.
4 ounces unsalted butter. (softened)
1 egg.
8 ounces Rich tea biscuits.
½ teaspoon butter for greasing.
8 ounces dark chocolate (for coating)
1 ounce chocolate (for decoration)

https://theroyalchef.com/the-royal-wedding-cake-recipe/

• Lightly grease a 6 inch by 2 ½ inch cake ring and place on a tray on a sheet of parchment paper.
• Break each of the biscuits into almond size pieces by hand and set aside.
• Cream the butter and sugar in a bowl until the mixture starts to lighten.
• Melt the 4 ounces of chocolate and add to the butter mixture whilst constantly stirring.
• Beat in the egg to the mixture.
• Fold in the biscuit pieces until they are all coated with the chocolate mixture.
• Spoon the mixture into the prepared cake ring. Try to fill all of the gaps on the bottom of the ring because this will be the top when it is un-molded.
• Chill the cake in the refrigerator for at least three hours.
• Remove the cake from the refrigerator and let it stand while you melt the 8 ounces of chocolate.
• Slide the ring off the cake and turn it upside down onto a cake wire.
• Pour the melted chocolate over the cake and smooth the top and sides using a palette knife.
• Allow the chocolate to set at room temperature.
• Carefully run a knife around the bottom of the cake where the chocolate has stuck it to the cake wire and lift it onto a tea plate.
• Melt the remaining 1 ounce of chocolate and use to decorate the top of the cake.