SSTP VPN support and Layer 2 traffic control on FortiGate / FortiSwitch

Hello,

In one of the company’s offices, we are planning to completely replace the hardware equipment, which includes the following:
1. FortiGate-120G Hardware
2. FortiSwitch-1048E
4. FortiSwitch-148F-FPOE
5. FortiAP-234F

What concerns me is that, for some of the offices, the only available option for a SSTP VPN tunnel is, due to the fact that the providers block our other VPN solutions.

From forums, documentation, and various sources, it is stated everywhere that SSTP cannot be used.

Is it true that it is not possible to use SSTP at all?
The other question is whether it is possible to control Layer 2 traffic between computers.
By this I mean: if one computer attempts to attack another computer, and both are connected to the same switch, is there an integrated tool on the switch that would allow me to detect and block such an attack?

Thank you in advance for your time.