'OpenVPN Server Speed' on 'Hardware & Performance comparison' website

Hi,

I'm considering purchasing a FWP or FWG, and have been mulling over the differences in the product comparison page. There's a row related to "OpenVPN Server Speed", and it states "120Mb" across both devices, with "WireGuard Server Speed" higher at "500mb".

Could someone please elaborate with this means exactly? Is the fastest possible speed I could achieve connecting home using OpenVPN 120Mbps or 120MB/s?

As an example, let's say my internet at home has 500Mbps for both UL/DL. I decide to connect to my FWP using OpenVPN from my laptop on a 1Gbps connection outside of home to access my network. Are my upload/download speeds capped by:
a) My home network at 500Mbps
b) The FWP OpenVPN functionality (what exactly would be the cap?)

If (b), why is this the case, and are there any plans to fix this? This is an important use case for me and I want to ensure I'm not exchanging my current VPN setup speeds (OpenVPN on a NAS) for something slower albeit safer.

Any input appreciated - thanks!

Edit: Having researched a bit more, am I right in stating the scenario above isn't even a functionality offered by FWP/FWG in the first place, without having 2 devices? At it's most basic, let's say I want to connect from my cellphone via OpenVPN to my home network when traveling. Is this something I can do with one device, and if so all questions above still apply?