You certainly can manually add your surnames as a 'signature" when you post.  i have done it a few times in the new platform, and it works fine, it's just text.

Even better for some users may be that the new platform has the option to store signatures, and automatically add then when sending a post. To use this, at the bottom of any JGen email you've received, click on "Your Subscription."  When that page opens,  scroll past the email preferences, and you'll see the section where you can add a signature, and adjust its settings.

Hilary Henkin

Researching:
Mogilev - BERLIN;  BELIISKI;  HENKIN - GENKIN;  MESCENIKOV;  POZ - POZE
Ekaterinoslav - KATZ; LAPIDUS;  LAVROTIN - LAVRUTIN - AVRUTIN;  PESACHINSKY; SHIMERNITSKY - SEMERNITSKY;  STEINHART
Roumania:  DONNENFIELD;  DOLLINGER;  RINCOVER - HARINCOVER;  WISENTHAL - VIESENTAUL
Harbin, China:  FELDMAN;  PENZNER;  SREBERK - SCHRIEBER;
Lublin, Poland:  KATZ;  JARMUSZ

(signature added manually)