Update: I am very happy with my decision to include kanji writing practice into my kanji studies.
I can’t be sure exactly how much of a positive difference it’s making to my retention of the kanji, their radical composition, their meanings, their readings, and their usage within vocabulary - but I’m sure it can’t be hurting.
I have a regime now where I practice the following every day:
- WaniKani reviews via handwritten kana into Tsurakame (iPad, Apple Pencil)
- KaniWani reviews via handwritten kanji/kana (iPad, Apple Pencil)
- Ringotan reviews via finger-written kanji (Android phone)
- KameSame reviews via keyboard IME (desktop computer)
- occasional Smouldering Durtles reviews via 12-key kana input when I’m on the move and don’t have my iPad (Android phone)
So far it’s turning out to be manageable, not overwhelming. In fact, I am quite addicted to getting my reviews done every day.
Each service and input method tests a different aspect of recall, and provides its own unique learning advantages. Some even give you helpful nudges. It always makes me smile to see the emoji version of the word appear in the suggestions when I’ve entered the answer correctly 
and a keyboard IME will warn you of incorrectly typed readings simply by not showing you the kanji you were expecting.
Now that I’m sold on using writing as a way to enhance my learning, my interest is piqued…
I notice in Ringotan that many of the radicals have slight variations to them. For example, sometimes the “moon” radical has curved feet, sometimes it does not.
I’d like to learn more about whether these variations have any significance.
To be sure, both Ringotan, and the iOS handwriting input, are very forgiving when it comes to including things like curved feet (or not). Ringotan just snaps your input to the correct place. As for iOS, if what you entered looks close enough to the kanji that you intended, and distinct enough from other similar kanji, then you get what you expected.
So is it purely stylistic? For example, the English ‘a’ character has a hook at the top when you see it in serif fonts, but the one we learned to write at school is more like the one you see in Comic Sans, and yet it means the same thing.
Or are there times when it does become significant? In calligraphy, for example?
Any good resources on learning more about this? Thank you!