I understand your problem. But as I said already, the current VLC version is just no media center solution and is not designed to be displayed on a display far away from the user.
This is not a media center issue. As we get older many of us have poorer eyesight. The playlist and controls are difficult to see. Even if we can see the controls it strains our eyes and damages our eyesight, speeding up our decline. To say nothing about users with genuine disabilities who can't interact reliably with such tiny fonts.
In 2019 there's no legitimate reason for an interface not to have user configurable size. Surely the health and safety of users are worth the minimal programming effort to do this.
Do you have parents? Grandparents? Are they able to use the interface comfortably? Why would you purposely release software that your own family members can't use safely without damaging their own health?
Only increasing the font size of the playlist will ultimately not help at all, because all other menus and buttons are still to small to be used.
Then fix the menus and buttons. It doesn't have to be pretty. Ever used an iphone-only app on an ipad? You can double the dimensions and it simply scales the graphics up. Sure it's not pretty, things are pixelated. But it's
usable. And dead simple to implement.