Chrome扩展declarativeNetRequest在Gmail中失效问题求助

我开发的Chrome扩展通过受控iframe抓取指定页面，抓取Gmail收件箱时请求失败，报错：

Refused to display 'https://mail.google.com/' in a frame because it set 'X-Frame-Options' to 'sameorigin'

但抓取Google Drive时可正常运行。

Gmail和Drive均设置了X-Frame-Options: SAMEORIGIN，我通过declarativeNetRequest移除该响应头及其他相关头来规避此限制，代码如下：

chrome.declarativeNetRequest.updateSessionRules({
    removeRuleIds: [1001],
    addRules: this.createRulesFor(patterns, [1001], tabId),
})

...

private createRulesFor(patterns: string[], ids: number[], tabId: number): Rule[] {
    let rules: Rule[] = [];

    rules.push({
        id: ids[0],
        priority: 1,
        action: {
            type: RuleActionType.MODIFY_HEADERS,
            responseHeaders : [
                ...this.createHeaderToRemove("X-Frame-Options"),
                ...this.createHeaderToRemove("Content-Security-Policy"),
                ...this.createHeaderToRemove("Content-Security-Policy-Report-Only"),
                ...this.createHeaderToRemove("Cross-Origin-Embedder-Policy"),
                ...this.createHeaderToRemove("Cross-Origin-Owner-Policy"),
                ...this.createHeaderToRemove("X-Content-Type-Options"),
                ...this.createHeaderToRemove("X-Xss-Protection"),
            ]
        },
        // XXX doesn't handle HTTP2 / 999, whatever that is (e.g. linkedin)
        condition: {
            // urlFilter: patterns[i],
            tabIds: [ tabId ]
        }
    });
    return rules
}
...
private createHeaderToRemove(headerName: string) {
    const lowercaseHeader = headerName.toLowerCase();
    const capitalizedHeader = headerName.charAt(0).toUpperCase() + lowercaseHeader.slice(1);
    return [
        {
            header: headerName,
            operation: HeaderOperation.REMOVE
        },
        {
            header: lowercaseHeader,
            operation: HeaderOperation.REMOVE
        },
        {
            header: capitalizedHeader,
            operation: HeaderOperation.REMOVE
        }
    ];
}

注：最初我基于待抓取URL注入通配规则，后来改为使用tabId。

绑定chrome.declarativeNetRequest.onRuleMatchedDebug后发现，规则对Drive匹配，但对Gmail不匹配。

推测差异源于：将基础URL通过Chrome复制为curl命令执行时，Gmail会返回3-4次302重定向后才返回200，而Drive直接返回200。若此为问题根源，需解答：

• a) 为何报错信息特指X-Frame-Options？
• b) 如何在扩展控制的tab内的iframe中监听并跟随302重定向？

内容的提问来源于stack exchange，提问作者user717847