It's a question of time and tools. You only have so much time to train so the time you spend in another stance means time not spent in your primary stance. So, accept that you won't get as good in your primary stance as you could if you train both.
Arts like karate train you in both from the beginning. But, and it's a big but, karate only trains in you a handful of techniques this way. So, you can become extremely proficient in 2 different stances because your goal is mastery of set number of techniques with both hands. You can throw a front kick with either leg proficiently but most people don't execute jumping side kicks with either leg equally well.
So, like someone else said - you should have a handful of things you do well from either stance. But, imo, not much point in devoting more time to it than that.