I also believe the "leg skill" should be above all MA systems. There should be just "leg skill". There is no such thing as WC leg skill or Taiji leg skill.
The problem here is that if you try to use SC leg skills in Tai Chi you have to violate the Tai Chi principles:
Good SC, bad TC!
The key is in something Windwalker said.
"In Taiji, what is referred to as 'kicking' is not isolated or different from any other type of movement practiced. All movements follow the same theory, based on the specific lineage of Taiji being practiced."
As such, it's part of a process, not developed or tested independently as an isolated movement.
So, if you want to add outside techniques to Tai Chi, you can do that! In fact, there is a version of Tantui which is trained in Chen Village even today. If you look at the history of Taijiquan it essentially is a collection of many popular arts of the time. My sifus broke this down for me since they also studied the underlying arts and showed me where they came from in Tai Chi. This is quite common. Feng Zhiquang added moves from Tongbei and Xinyi Liuhe to Hunyuan Tai Chi, moves that fit but perhaps weren't included, or were lost over time. Also look at Yang style. Several moves in Yang style that are not found in Chen style were added from Yang's mother art, plum blossom. Putting his own move in there was done to show his skill and that he had gone out the door. Wu Style as mentioned is a great example, it is highly compatible with SC because as I recall, the founder had extensive experience as a martial artist already. You see this all the time in Bagua and other arts too, the most successful students were already martial artists. Consider this deeply!
There is still a version of Tantui that is practiced in Chen Village, to this day.
Based on this (and since it is relevant, my experience as a beginner at Wu's Tai Chi way back in the 90s,) if you wanted to add leg skills to your Tai Chi, I would first ask you, if you are mature enough in your Tai Chi training to take responsibility for your Tai Chi training by yourself. Meaning, you are ready to "go outside of the house". If you do this too soon you will destroy your chance of getting ability in Tai Chi. That is because you have started training things that do not achieve your "Tai Chi goals", and from a Wu De perspective you have gone against your teacher's advice and teaching and to do what you want to do instead. It's a bit rude, but, western people have a hard time understanding this perspective. For example, do you think this champion is right or wrong?
What a difficult moral quandary!
So, now that we see you are ready to leave the house, I would suggest immediately adding leg pulling skill. That is a direct translation from Chinese. Why, because it immediately supports your Tai Chi within the framework of Tai Chi. Second, take on single movement practice. Start kicking bags. Not obsessively, but enough to get the hang of it. You might also want to add a brisk morning walk or jog -- 20 or 30 minutes? And, if you still feel the need to train, you can add Tantui to the mix. I like unaltered 10 roads Tantui for this purpose since it's minimalist. You can get away with Central Institute (i.e. Han Ching Tan) 10 roads Tantui too.