SlowiPadPanGesture.swift

import UIKit

var startTime: CFAbsoluteTime!

class ViewController: UIViewController {
    let movingView = UIView()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        movingView.frame = CGRect(x: 200.0, y: 100.0, width: 200.0, 200.0)
        movingView.backgroundColor = .systemBlue
        view.addSubview(movingView)

        let panGestureRecognizer = InstantPanGestureRecognizer(
            target: self,
            action: #selector(panned(panGestureRecognizer:))
        )        
        movingView.addGestureRecognizer(panGestureRecognizer)
    }
    
    @objc private func panned(panGestureRecognizer: UIPanGestureRecognizer) {
        if panGestureRecognizer.state == .began {
            // Takes 0.01 seconds on iPhone 🐇
            // Takes 0.75 seconds on iPads 🐢
            print("Time elapsed: \(CFAbsoluteTimeGetCurrent() - startTime) s.")
        }
    }
}

class InstantPanGestureRecognizer: UIPanGestureRecognizer {
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
        super.touchesBegan(touches, with: event)
        state = .began
        startTime = CFAbsoluteTimeGetCurrent()
    }
}