Matcha swiss roll with tsubuan anko filling

After doing extensive research on swiss rolls and the different methods, I settled on a recipe that was matcha with red bean filling and which most matched my pan size, so there would be very little adjustments.

I settled on CWD and used some of the tips from other recipes. I like this recipe because it's very easy to remember.
https://cookingwithdog.com/recipe/matcha-roll-cake/

Ingredients
4 eggs, separated when out of the fridge and left to come to room temp
40g sugar
40g cake flour
1 tbsp matcha powder

Filling
120 ml heavy cream (full cream)
1 tbsp sugar (I omitted this as the anko is already very sweet)
120g anko (I used tinned anko because I read from Kitchen Tigress that the tinned version uses Hokkaido beans which is far more fragrant than beans from China. Saves me work, why not? I didn't bother draining the beans unlike her though.)
80g sweetened beans (substitute with fresh fruit; I omitted this)
Powdered sugar to dust

Method
1) Line the tin on the bottom and sides. My tin ie 24.5*34.5 cm.
2) Sift the flour and matcha twice. Sift onto a parchment paper (which you can save for later when you invert the cake)
3) Clean a bowl and the beaters with vinegar. Separate the eggs.
4) Using the beaters, beat the egg white until foamy. Add ⅓ of the sugar. Beat on medium until incorporated and add the next ⅓ of the sugar. Increase the speed and beat until stiff peaks.
5) Using the same unwashed beaters, in another bowl where the yolks are, add the remaining sugar and beat until pale and foamy. Remember to beat the yolks after the whites otherwise the whites will not rise.
6) Add the flour and matcha mixture to the yolk in two batches and use a whisk to fold in until all the flour is wet.
7) Add the meringue in 2 batches. The first batch will loosen up the batter so you don't have to be too careful but be more careful and use the whisk to fold in the second batch. Pour the batter into the bowl with the remaining meringue. Using a spatula, carefully fold in the batter so as not to break the foam.
8) Pour into the prepared tin. Use a scraper to spread the batter to the sides and corners and create a nice flat surface. Drop the pan on the table top several times to knock out big air bubbles.
9) Bake at 170 deg C for 25 mins. Produces a 2cm tall cake.
10) Remove from the oven and drop pan on the table top to prevent shrinkage. Invert the cake onto a parchment (from the sifted flours) and gently peel off the back. I decided that the bottom looked nicer than my crust so inverted it back again.

The crust or top of my cake. Not very flat because I didn't use a spatula to flatten!

Cover with another parchment and the pan to let cool. Some bloggers cooled on a wire rack but it didn't really make a difference to me.

11) While cooling, make the filling. Whip the double cream to stiff peaks and fold in the anko. Leave in the fridge while waiting for the cake to cool.
12) Once the cake is cool enough to handle, at one short edge, cut diagonally 45 degrees to make a nice seam. I didn't wait until the cake was completely cool, just cool enough not to melt the cream.
13) Spread the anko cream but leave 1cm from the diagonally cut edge as when you roll, the cream gets pushed to the ends.

The bottom of the cake becomes the outside. Pockmarked face because my pan has a braille-like raised surface supposedly for airflow!

14) Using the parchment to help, roll from the uncut short edge. Place the roll seam side down. Transfer to a clean parchment and use a spatula or ruler or knife to tuck the parchment tightly into the roll. Cover with the parchment and a plastic film. Leave in the fridge to cool from between 3 hours to 3 days. (Tigress recommends 3 days so that the cream's moisture melds with the cake)

Recipe feedback
- Initially once cool, the cake seemed very dry since there is no oil and matcha-based pastries always seem to be dense and dry. It wasn't very spongey too, maybe because I over-beat the egg whites until they became watery and 'crumbly'. Also, perhaps 25 minutes baking time was too long. I will have to re-attempt this another time.
- Cak wasn't too sweet. Excluding the sugar in the cream helped because the anko is very sweet.
- Cake is 2 cm tall.
- After leaving to chill in the fridge overnight, it really seemed much less dry as the moisture from the cream had permeated into the cake.
- Updated: Cake was eaten on the 2nd, 3rd and 4th day. It was moistest on the second day, so-so on Day 3 but by Day 4, it had dried out. As such, not a good idea to follow Kitchen Tigress's advice to keep to Day 3 because my pastries last more than a day in my house, so I'll be eating very dry cake from Day 4 onwards.