125mm vs 100mm dropper — am I pushing my luck with this saddle height?

Looking for some real-world input before I buy a dropper.

I’m riding a 29” hardtail MTB with a 27.2mm seat tube and internal cable routing. My saddle height is already dialed in and I don’t have much extra room to play with.

Key measurement:

From the top of the seat collar to the center of the saddle rails, I have about 165 mm at my correct pedaling height.

Dropper I’m considering:

* Diameter: 27.2 mm

* Travel: 125 mm

* Total length: 425 mm

* Routing: Internal

* Type: Cable-actuated mechanical dropper

I contacted the seller and they said the stack height (collar to saddle rail center when fully compressed) is approximately 155–170 mm, depending on clamp design and saddle rails.

That puts the 125mm option right on the edge for me:

* If it’s closer to 155–160 mm, it should be fine

* If it’s closer to 170 mm, the saddle may end up too high

I might tolerate a few mm higher, but I’d rather not compromise fit or risk knee issues long term.

Question for those with experience running droppers in tight setups:

Would you risk the 125mm here, or is 100mm travel the smarter, no-regret choice?

Picture of the bike: https://dyncdn.thg.dk/img/112950110_0_m_650_1100.JPG

Thanks in advance.