I just found out that it's possible to alter Blockland's resolution manually.
I now can film widescreen videos without using fullscreen and making my laptop angry at me.
Three 16:9 resolutions (type this into console):
setres(1140,640);
setres(1030x580);
setres(850,480);
It prevents resolutions smaller than 640x480 and resolutions larger than your monitor.
Now why didn't I know about this eight months ago?