Unused reality checks?

I have been doing reality checks using many triggers almost flawlessly every day. However, I never perform any of these reality checks during my dreams even when I encounter the triggers. How strong must the habit be in order for me to perform them in dreams?

You aren't remembering to do reality checks during your dreams because you're dropping the intention that allows you to remember to do them during the day.

While you're falling asleep, maintain your intention to do a reality check upon experiencing a trigger. You know it's coming! All you have to do is wait for it, anticipate it, and be ready to catch it when it comes, just like you do every day while you're awake.

You should be familiar with perspective memory. It's the memory that reminds you about something in the future when you place an intention, conscious or subconscious, to remember it or doing it. For example, when you turn on the stove and say that you need to turn it off one hour from now, an hour passes, and suddenly out of the blue you remember "oh right it's time to turn off the stove". This is no voodoo magic, it's your perspective memory. Another example is when you say you want to remember to buy gum next time you pass a store. Then when you pass a store, you would remember the gum. "Oh yeah I wanted gum next time I passed the store"
There are 2 kinds of prospective memory, time related and event related. First one is remembering after a certain period or at a certain time in the future (like example one). Other is event related, having something trigger your remembering (like in example 2 and your case).

So, you must place an intention before going to bed about whatever you want to remind you you're dreaming. Also, very important, you should train your PM. It'll become stronger. Training it is easy; just use it! First thing in the morning, write a list of a couple things you know would happen frequently during your day, then place the intention to RC each time one of them shows. After a month or so, you can make it harder by adding more than just 2 targets, and so on and so forth.