That's not the Smith Morra gambit.
The Smith Morra gambit is 1.e4 c5 2. d4 cxd4 3. c3
take a look at chessgames.com opening explorer. Taking the pawn is not a popular option:
You are talking about Old Benoni Defence here. Smith-Morra Gambit is actually a counter to the Sicilian.
Declining Morra by playing 1.e4 c5 2. d4 cxd4 3.c3 Nf6 and transposing to a c3-sicilian seems reliable as you have to be prepared for a c3-sicilian anyway. hope this was helpful :)
I found an early novelty which gives Black the advantage in all variations, verified by Stockfish and several masters. I published my analysis on Chessable.
https://www.chessable.com/mangle-the-morra/course/19264/
https://new.uschess.org/theory/bust-smith-morra-gambit/
"US Chess is running a contest: can you bust the bust? Send your counter-efforts to US Chess Digital Editor John Hartmann <john.hartmann@uschess.org> on or before August 15th. We will publish the best responses to Logozar’s claims, and give Logozar a chance to respond as well. Two prizes – one from US Chess Sales, and one from Chessable – will be awarded those submitting the best analysis." - John Hartmann
This gambit destroys me everytime. Dodge the pawn and you have a bigger problem. Kill the pawn you lose an essential center pawn. Let it kill your pawn? I don't know. But this opening is terrorizing my games and I need help. Everyone over 1300 seems to play this as a challenge to my d4 and I don't know how to counter it. They don't care if D4 is my first move or not! I'll even use the reti opening to start with to see how they'll respond but they always shut down D4!!!
Please help? I'd love to know how to shutdown this dreaded gambit.