Extending existing AP-100 coverage with APX series

Question

I have a site with a Sophos XG115w and three AP-100 access points that I need to extend wireless coverage. I can only do it over the air due to cabling difficulties. According to Sophos documentation, you cannot create a mesh network between different series, such as the APX and AP. Since the AP series is EOL, I wonder if I could just get a few APXes and figure them as plain old repeaters with one radio joining the existing network as a wireless client while the other radio serving a different SSID to regular wireless clients. 
 Is this even possible with a centralized Sophos XG or Sophos Central management interface? 
 I am pretty sure this is a standard feature on most standalone APs. 
 I'd appreciate it if anyone has any insight. 
 
 Daniel

Tejas Kashyap · Answer

Hi Daniel, 
 Forming a mesh between AP and APX is not possible if you are managing the access points through Sophos XG. This should however, work if you are managing access points through Central. While we do not endorse forming a mesh across platforms as the underlying implementations are different, there is nothing preventing you from forming one when APs are managed through Central to address the above-mentioned use case. 
 https://support.sophos.com/support/s/article/KB-000037097?language=en_US 
 -Tejas