If the UI ever supposedly comes to a change where the old theme will be replaced with a newer one then before that happens you should know why it's not a good idea. Modern UI is almost everywhere, some people have brought up the idea to replace the "dated" older UI. My question is, do you REALLY want to do what everybody else's doing with THEIR website? I mean, you can do whatever you want to YOUR website but consider this: why am I doing this? Are you doing it because of the new modern UI trend popularized by Microsoft? (Microsoft really popularized modern UI, look it up if you don't believe what I'm saying). What I think is; you should do what YOU want to do, not what everybody else's doing. And if that IS what you want to do then go ahead. I must say though, a flat UI makes a 2D screen boring. A 3D UI (like the one Immunet is using for their program rn.) establishes what's boring to new, futuristic, and special. My idea is this: You can change whatever you want, but don't make it modern UI. This's just a constructive opinion, you don't have to do what I tell you to do, but when you have almost every single website you look at SHARE ONE ENTIRE UI, I start to lose sanity. What I will like is if you change the UI to something less "dated" but keep the 3D effect. You can even make a whole new UI yourself.