Vampires with the full sun protection perk or in the shade (such as holding an umbrella) will not run inside. In addition, if the interaction gets cancelled, the vampire sim will keep trying to run inside periodically if they're still burning. For example, a vampire who's weak to the sun, or who got a bit too close to death, might hiss a little extra and get a little panicked while running, while one who's got some sun protection might only get annoyed. I've even added some little reaction animations and buffs before, during and after for a little extra flavor, and these will differ depending on how badly burnt/close to death the vampire is, as well as on if they have any of the sun-related perks or weaknesses. So, I managed to copy the 'run inside' interaction from Seasons that sims do when it thunders or rains and edited it and made it get pushed on vampire sims being burned by the sun.
It turned out that the tunings for the vampires didn't have any coded responses to the sun buffs or timer beyond playing some annoyed idles. What this mod does is to fix the issue of vampires not doing anything to save themselves when they're burning in the sun. This one has actually been up on curseforge for a little while now, I just kinda forgot about posting about it lol. I made another mod too self-preservation for the poor vampires!