Until this is resolved, this is working well for me as a userscript...
// ==UserScript==
// @name Responsive Profile
// @version 0.1
// @description Display a user's Stack Exchange profile without horizontal scroll bars
// @namespace miken32
// @author Michael Newton
// @grant none
// @license GNU GPL v3 or later (http://www.gnu.org/copyleft/gpl.html)
//
// @include https://stackoverflow.com/users/*
// @include https://meta.stackoverflow.com/users/*
// @include https://serverfault.com/users/*
// @include https://meta.serverfault.com/users/*
// @include https://superuser.com/users/*
// @include https://meta.superuser.com/users/*
// @include https://askubuntu.com/users/*
// @include https://meta.askubuntu.com/users/*
// @include https://stackapps.com/users/*
// @include https://*.stackexchange.com/users/*
// ==/UserScript==
var rules = [
"html, body {min-width: 0}",
".user-show-new .user-rep-chart-summary .user-rep-chart-summary-tooltip {width: calc(100% / 32 - 3px)}",
".user-show-new .user-rep-chart-summary .user-rep-chart-summary-bar {width: 100%}",
".user-show-new .user-panel .answer-hyperlink, .user-show-new .user-panel .question-hyperlink {width: auto; padding-left: 10px}",
".user-show-new .user-panel table {table-layout: fixed}",
".user-show-new .user-rep .rep-amount {padding-right: 0}",
".user-show-new .count-cell, .user-show-new .icon-cell {width: 40px}",
".user-show-new #user-tab-answers .answer-votes, .user-show-new .user-panel .mini-counts, .user-show-new .user-rep .rep-amount .rep-down, .user-show-new .user-rep .rep-amount .rep-up {min-width: 0; width: 100%}"
];
if (document.querySelector("body.user-page")) {
var style = document.createElement("style");
style.textContent = rules.join("\n");
document.getElementsByTagName("head")[0].appendChild(style);
}