T-Deck stock whip vs. Muzi vs. best hinged antenna? (Beginner Qs.)

I am considering diving into Meshtasic. Not going to build a node myself, but comfortable tinkering on the software/configuration side. Primary use: hobby/fun. Occasional use: hiking with no cell coverage.

My location is not good: a high-rise on the edge of a dense suburb, but my windows face away from the city. Miles of sparsely populated hilly terrain. I can’t install nodes anywhere outside my apartment, so I accept that I MAY not find any connections without leaving home. But I still want to maximize my chances!

My node goals:

• Maximum range sitting on a windowsill connected to USB power (not solar).
• Slim enough to vanish into a back pocket.
• Standalone/keyboard so I can hand it to others to use immediately.
• TWO nodes—or else those goals are nonsense! And also so I can test sending to each other. And to have a pair for hiking with someone else occasionally.

My week of research inclines me toward buying these:

• SenseCAP T1000-E for the pocket node, connected to my iPhone.
• LILYGO T-Deck Plus with external antenna for the higher-range/windowsill node that will occasionally be carried as well. (I know not to invite hassle by getting the T-Deck without exposed SMA connector.) I’m in the US, so would be getting 915 Mhz gear.
• (Some kind of SD card for T-Deck message history and maps? I have to figure out what kind it needs and whether it already comes with one.)

Antenna questions:

• Would I see any likely benefit swapping the T-Deck’s stock LILYGO whip antenna for a 17cm Muzi whip on the windowsill? (Both look similar in length but people seem to like the Muzi.)
• Is there a longer/bulkier/better antenna than those that I could choose for the windowsill? (I can always swap the bundled whip back on for outings.) I want the best range from my apartment, but since I have no specific target to reach, I don’t want narrow directionality.
• Assuming that keeping the antenna vertical is important, what is the best hinged antenna? When carrying the T-Deck, a non-hinged antenna is going to be at a weird angle that could be solved by a hinge. And on the windowsill, a 90° bend would let me lay the T-deck on its back, instead of rigging some awkward vertical mount with USB power coming out the bottom.
• Is that "best hinged antenna" worth choosing over the longest/best "non-hinged" for my situation?

Lesser questions:

• Any reason not to save a few bucks by choosing the LILYGO firmware and then flashing to Meshtastic UI myself via the web flasher?
• I’m not planning to use MQTT, but if it comes to that, if I set my windowsill node up that way, can my Bluetooth/iPhone T1000 hop through it to reach faraway nodes? Or would I have to connect my iPhone (via the recently-added TCP option) directly to the MQTT windowsill node itself?
• Is the Edge browser sufficient to flash firmware on a recent Mac? (Chrome is more intrusive than I want to install.)

Thanks for any advice!