In France a lot of customers uses Ubiquiti (EdgeRouter/EdgeMax product category) routers for 1Gbit Fiber Internet Lines. It works well with OpenVPN (I can provide a guide) and I am sure L2TP/PPTP works also perfectly . But I was not able to configure IKEv2/IPSec which seems to be faster and consume less CPU...
In my point of view removing the support of SSTP/L2TP/PPTP is a great idea for you and us (even if this may imply changing hardware).