Hey Grail, yeah this is an important think to be aware of. When You take pills orally they are processed through the liver, this puts strain on it. The same would be true if You took paracetamol every single day. It's a small amount of stress but it can build up and lead to reduced liver function. This is why we keep an eye on liver function during blood testing for hrt. Basically it means Your liver is always working hard to remove the stuff You're putting into your body.

If you use gel or injectables or even sublingual pills, it bypasses Your digestive system and liver and goes straight into the blood where it can be used by Your body. There is no long term deleterious effect on Your liver that way. After 6 years on pills I think it might be sensible for You to consider shifting intake method. If You have a doctor supervising Your treatment You could talk with them about it.

At the very least maybe get some liver function tests if You have that option available.

I don't think there's any reason for You to panic, I know plenty of girls that have been on oral E for years. The problems with liver function take a very long time to build up. This is really about the effects after 10, 20, 30+ years that we're trying to avoid.