Can I toggle transparency when I change the bg option?

[AL-Man64]

I usually code in a dark theme, however sometimes, e.g. in well lit conditions, I would prefer to code in a light theme (i.e. latte), and this is well covered with set bg=light and vice versa.

I also like to have my background transparent, but this doesn't play well with latte, since it doesn't change my terminal's dark background to something more appropriate.

Can I automatically toggle transparency to get around this, or have this theme change my terminal's (alacritty) background when I change to a light background?