on MC2, "Springboost Hits" or SBHs, are when you perform a normal boost and once you pass the zippers, you immediately hit the second spring and perform a sand cut. Observe on my 13"98 flap PR video at the beginning of the start of Lap 2 (ending lap 1) (at 0:24) It's slightly quicker than a normal Non-LB perform.
Longboosts are harder than SBHs and sometimes, I call them safe-LB


I scored 1'12"94 on MC2 with 0/5 SBHs


A 5/5 SBH with tighter NBT turns would probably be viable for a upper 1'10"xx or 1'11"xx
Longboosts, however, would surpass that   to a good 1'05"xx with skill like ScouB and Lafungo.

I mean you could always just make a forum thread with a leaderboard for it

Just noticed I wrote 'nad' instead of 'and' in one spot of that massive theoretical hyperlink. Fixed now tho, lol.

It's a shame the forum automatically formatted it the way it did instead of keeping it in one long line. Kinda loses its punch I'd say.

Have you ever done this strat 5/5? Seems like it's kind of a fluke occurrence and not really viable to do all the time anyway.