The dipole antenna coming with the HDZero whoop lite kit is fine. I do not think using SMOL makes a really noticeable difference (indoors at least), but it is just the right length, only 0.4g and have survived well enough on my quads. I'd be actually very happy to source the short whip antennas that Mobula6 HDZero whoops come with. At just 0.23g they help to keep builds light and do not drastically differ in performance either. I have not done any rigorous range test / comparisons, but I do use those 3 mentioned options in many tiny whoop builds and they all feel kinda same'ish in the environments I fly (mostly indoors, or from inside the house to avoid mosquitoes). On bigger builds there are more options, but then, also more materials blocking your antennas than on tiny whoops.

I measured that I used M1.4 8mm long screws. I have no clue from which kit I got them and they are not easy to source indeed.

Another question, should I solder vtx power to 5v pad or to power lead? I soldered to 5v and I have rainbow as soon as I arm whoop.

VTX is supplied voltage directly from power leads.

ok so maybe thats the problem here, bit I thought that 5v pad will give constant 5v, so even better than power lead?

No, HDZero and Walksnail 1S VTXs have their own step-up circuitry and most Flight Controllers struggle to supply enough power for external VTX anyway, so direct to power leads is the only way in most cases.

I figured out that the long screws came with the Walksnail/Avatar HD Mini/Nano 1S Lite kits, 2 different lengths which covers you 2 whoop builds. When making Walksnail CrossF4 FC build I put only one M2 O-ring underneath it instead of 2 and in this I think 8mm M1.4 screws were enough (works as long as you keep the VTX to FC wiring neat between the boards). 8mm M1.4 screws show up on Amazon shop searches, anything longer seems hard to find.

I am getting around 3:30+ minute flights indoors with decent BT2.0 ~300mAh batteries. In wide open space with more throttle, probably quite a bit less. HDZero version is slightly lighter and VTX drops off at slightly lower volts, thus, you can milk more flight time out of HDZero than Walksnail, but it is good to see both systems improving constantly. Running both VTX at 200mW since Walksnail seems to not behave that well at 350mW without much benefit over 200mW.

Very cool, thank you for the info

Thanks for the info

Both platforms and options keep improving, so the decision is more about what solution for what kind of flying / applications. I have more toys than I have time, so instead of choosing, I can afford to play with most options. I do not race, but for whoops & smaller quads I definitely prefer HDZero. I like my Mobula6 HDZero whoops indoors the most, but this new "BetaFPV Meteor65 Pro" frame and new 35mm props provided an interesting option to have something in-between 75 and 65 mm size. Walksnail has potential for being my preferred choice on airplanes (especially with the new V2 & Pro camera options). I also still use DJI "naked Vista VTX" on 2S and bigger quads. If Walksnail 1S could also accept more than 1S voltage like HDZero Lite and/or could also shrink down their larger VTX further (to naked Vista dimensions and weight), then it becomes more versatile option, but until then I keep using all 3 probably.