Join Date: Feb 2017
Location: Casa Grande, AZ
The jerky acceleration is probably the stock electronic boost controller which is crap and it's highly recommended to replace it.
As far as the coolant, there have been some instances of leaky turbo cooling lines. Might crawl under and check that. (might be able to see them from the left side of the engine bay) My suggestion would be to fill it back to max when the engine is cold and see if it goes down again.
'17 6MT Base | Lap3 Tuned | Autocrosser / Canyon Carver / 14.2 @ 99 mph
B&M SS w/SXTH Bushings | N-Line Mounts | GFB Mach 2 | SXTH Intake, Dual OCC, FMIC
Straight Midpipe | JUN B.L. Axleback | KDM Tuners Slotted Rotors, Stainless Lines | Porterfield R4-S
YSR Coilovers (8k/6k) | Pierce 4-point Tie Bar | SXTH 22mm RR Sway | WL/SP CA Bushings
XXR 527 18x8 +45 | Firestone Firehawk Indy 500 245/40