A teaspoon of liver every other day is not going to cause Vitamin A toxicity. You are at far greater risk for deficiencied that organs, especially liver, can resolve.
Vitamin A alarmism comes from 2 datapoints: studies showing synthetic vit A at 100s times what could reasonably be obtained through beef liver, and an anecdote about a dude dying from polar bear liver, which has 100x retinol to beef liver.
Eat in moderation and a single liver will last at least 3 months. Ignore Vitamin A hysteria.