Both Asternic and FOP2 will work with old and recent versions of FreePBX.
Asternic reads the queue_log file… that is an Asterisk feature that is currently enabled in default configs in major Asterisk based distributions including FreePBX. If its not enabled, it is very easily enabled. Once you have your Asterisk loggin queue activity into that file, Asternic will work.
We even wrote a FOP2 plugin that when connected to Freeswtich, it will interprect mod_callcenter activity and write a queue_log file for it, so queue reporting is also available on Freeswitch based mod_callcenter setups.
Both FOP2 and Asternic work with PHP 5.x up to 7.x, and works with old and recent Asterisk versions also. When future Asterisk versions come in, they might be some issues when dealing with AMI (realtime monitoring), and a couple of months for the software to catch up with those changes. Usually the inconveniences because of AMI changes are minor, not showstoppers. FOP2 itself barely uses PHP, it does so for some plugins, not for the core switchboard functionality, that means that you can have a fairly functional switchboard with no php support at all in your box.
Many people wonder if our products will work with FreePBX version XXX, the answer is always most probably YES. Unforuntalty we were not allowed to say so that on our documentation or web sites.
In any case, you can download the software and start a 30 days trial for free without any kind of intervention or interaction with us. That way you can try if it works or not.
A final note, its not the place but I noticed Lorne chimed in… in a recent FreePBX distro update it seems there was a change in the logrotate configuration for the queue_log file. That change might cause issues as the queue_log file might be rotated by asterisk, but asterisk logger is not signaled about it, so Asterisk will write NEW events on the ROTATED log file. I should report this on some FreePBX Distro bugtracker, but I really do not know if that exists… its a problem with the distro logrotate file, not with the Freepbx software itself.
If there are Asternic users reading this post, you might want to add the postrotate config in the queue_log section of your /etc/logrotate.d/asterisk file, like this:
create 0640 asterisk asterisk
su asterisk asterisk
/usr/sbin/asterisk -rx 'logger reload' > /dev/null 2> /dev/null