Granted.. it's not a fair comparison, as SFFT is run much differently (although SFStL does seem to be copying style/ideas from SFFT now with the updates).
but Joker: Carnival of Chaos (previously planned as Joker: WildCard) is the exact same ride that's going here.
At SFFT:
they started clearing for Foundation pour on 2/23/19
footers poured by 4/7/19
ride pad, and queue house done by 4/28/19
ride parts arrived on site 5/18/19
main supports bolted together (on ground) and LED light package installed 5/25/19
ride vertical, and 1st testing on 6/26/19
finishing touches over the next week.
Ride was ready to go by 7/14/19, but did not open until 8/10/19 due to waiting for inspections.
so from actual starting of pouring the footers, until ride was up: ~3 months.
and from actual RIDE PARTS ARRIVING ON SITE until ride was up? ~2 months.
(all dates from construction updates at SFFT source)
So, yeah.. they COULD still hit mid/late summer, if they get it going.