Sure, it works with adding a usergroup as well. The limits are implemented as XenForo "integer" permissions and default XenForo implementation of such permissions apply, when a user has different usergroups. In general, the usergroup with higher value for the permission gets higher priority, and "unlimited" option applies with highest priority. So, in your case, the limited usergroup should have the values defined, and the "upgraded" usergroup should set it to "unlimited".
The message is shown instead of XenForo's default message about not having permission to post a thread:
View attachment 162437
The message is too much complicated to be one single phrase, as it many cases it has to shown different content (e.g. the time to wait is only 1 minutes, it does not make sense to write that 0 days, 0 hours and 1 minutes are left).
If you want to have all these details in your message, than you need a template with several phrases and conditions as well. Here is the content of the template. Feel free to suggest if you more optimal way to implement this, that would match your needs and the needs of users who use it its current form.
Code:
<span class="element">(
<xen:if is="{$posts}">
{xen:phrase alpl_you_can_post_in_this_thread}
<xen:else />
{xen:phrase alpl_you_can_post_in_this_forum}
</xen:if>
<xen:if is="{$postedTimeInfo.days}">
{$postedTimeInfo.days}
<xen:if is="{$postedTimeInfo.days} ==1">
{xen:phrase alpl_day}
<xen:else />
{xen:phrase alpl_days}
</xen:if>
</xen:if>
<xen:if is="{$postedTimeInfo.hours}">
{$postedTimeInfo.hours}
<xen:if is="{$postedTimeInfo.hours} ==1">
{xen:phrase alpl_hour}
<xen:else />
{xen:phrase alpl_hours}
</xen:if>
</xen:if>
<xen:if is="{$postedTimeInfo.minutes}">
{$postedTimeInfo.minutes}
<xen:if is="{$postedTimeInfo.minutes} ==1">
{xen:phrase alpl_minute}
<xen:else />
{xen:phrase alpl_minutes}
</xen:if>
</xen:if>
<xen:if is="{$postedTimeInfo.seconds}">
{$postedTimeInfo.seconds}
<xen:if is="{$postedTimeInfo.seconds} ==1">
{xen:phrase alpl_second}
<xen:else />
{xen:phrase alpl_seconds}
</xen:if>
</xen:if>
)</span>
Thank you!