The only thing I will add is make sure your center of gravity isn’t above or behind the rear tire. A good friends father used to run the local bike shop where I grew up. His dad took two Huffy boys bikes and stacked them making a tall bike. I rode it once as a kid. That bike was sold along with the bike shop when his dad died. A couple years back my friend built himself one identical to the one his dad built (based off of old photos) . The only problem he has is going up any incline, if he doesn’t lean way forward, the bike wants to wheelee.
Truth, as my current tallbike has the same tendencies. To combat this phenomenon, the extra long effective top tube (2 1/2" longer and being able to move the saddle forward a bit) and heavier construction when extending both the head tube and steerer tube should help quite a bit. Others have negated ths effect by running a smaller front wheel as well.
Even so, riding a wheelie on a tallbike makes the spectacle more enjoyable sometimes. I've looped my current one several times, but my own tallness makes it an easy dismount.
The first pic is my suicycle multi speed modern high wheeler.
The second pic was the first design of my bike just before I took it out for a test ride. Ride didn’t go as planned, it was frontheavy and I hit a small hole at the end of my driveway and went over the bars breaking my arm and many ribs. Back in the shop I moved the seat back and reworked the handle bars, painted it, rode it one more time , then retired it. I’m getting to old to break bones !