SVG Path Line Animation in IE

I have some path animations on a page and they work fine in all browsers except IE10/11. However I have some much more simpler animations doing the same thing on other pages, just with fewer of them, using pretty much the same code and they seem okay.

I think it may well be a performance bottleneck or so associated with IE.

If you view http://ift.tt/1IRIjK2 in IE10/11 you'll see there is quite a noticeable problem where the svgs appear glitchy or not fully rendered. Can't quite figure out what it is.

The relevant JS code from codepen:

    var cfg = {
            easing: [0.165, 0.84, 0.44, 1],
            duration: 1200,
            delay: 500,
            layerDelay: 7000,
            width: 28,
            positioning: true,
            colors: [
                    '#027CA5',
                    '#75B5C6',
                    '#00FFD0',
                    '#00B994',
                    '#BEF5FE'
            ]
    }

    $('.shape-layer').each(function(i) {
            var $this = $(this);

            setTimeout(function() {
                    var $paths = $this.find('path');

                    strokeSetup($paths);
                    strokeOut($paths);

            }, cfg.layerDelay * i);
    });

    function strokeSetup($el) {
            $el.each(function(i) {
                    var $this = $(this),
                            pLen = Math.ceil($this.get(0).getTotalLength());

                    $this.css({
                            'stroke-dasharray': pLen,
                            'stroke-dashoffset': pLen,
                            'stroke-width': cfg.width
                    });
            });
    }

    function strokeOut($el) {
            var pathCount = $el.length,
                    iterationCount = pathCount;

            $el.each(function(i) {
                    var $this = $(this),
                            pLen = Math.ceil($this.get(0).getTotalLength()),
                            color = cfg.colors[getRandom(0, cfg.colors.length)];

                    setTimeout(function() {
                            $this.css({
                                    'stroke': color
                            });

                            if (cfg.positioning) {
                                    var side = ['top', 'bottom', 'left', 'right'],
                                            cssO = {};

                                    $this.parent().css({
                                            top: 'auto',
                                            bottom: 'auto',
                                            left: 'auto',
                                            right: 'auto'
                                    });

                                    cssO[side[getRandom(0, 1)]] = getRandom(0, 40) + '%';

                                    var firstPos = cssO[Object.keys(cssO)[0]],
                                            sideAmount = (parseInt(firstPos) < 20) ? 100 : 20;

                                    cssO[side[getRandom(2, 3)]] = getRandom(0, sideAmount) + '%';

                                    $this.parent().css(cssO);
                            }

                            $this.velocity({
                                    'stroke-dashoffset': 0,
                            }, {
                                    duration: cfg.duration,
                                    easing: cfg.easing
                            });

                            if (!--iterationCount) {
                                    strokeIn($el);
                            }
                    }, cfg.delay * i);
            });

    }

    function strokeIn($el) {
            var pathCount = $el.length,
                    iterationCount = pathCount;

            $el.each(function(i) {
                    var $this = $(this),
                            pLen = Math.ceil($this.get(0).getTotalLength());

                    setTimeout(function() {

                            $this.velocity({
                                    'stroke-dashoffset': pLen
                            }, {
                                    duration: cfg.duration,
                                    easing: cfg.easing
                            });

                            if (!--iterationCount) {
                                    strokeOut($el);
                            }
                    }, cfg.delay * i);
            });
    }

    function getRandom(min, max) {
            return Math.floor(Math.random() * (max - min + 1)) + min;
    }