Blue Gelato 41 can stretch quite a bit, but I wouldn’t expect a crazy 2–3× sativa-style stretch from most phenos. Barney’s Farm lists it as 60% indica / 40% sativa, with indoor plants finishing around 110–150 cm and a 9–10 week flowering period. �
Barneys Farm Cannabis Seeds + 1
From the structure in your photo, I’d plan for roughly 1.5–2× the current height after flip, with phenotype variation either way. Since you’ve already got a SCROG net in place, I’d keep tucking through the first 2–3 weeks of 12/12 and then let the tops rise.
If height is tight, I’d flip a little earlier rather than waiting for the net to be completely packed, this strain should do a good job filling the remaining gaps during stretch.