NanoVNA and LiteVNA questions

[hem213]

Hello everybody!

Recently I bought a NanoVNA as a part of my lab but I did not research all the options enough and now I am reconsidering. The issue is that I am very interested in antenna, filter, and mixer design exclusively in the microwave range, really nothing else. When I first bought a NanoVNA, I thought which seller was the most important consideration and then the maximum freq when figuring out which NanoVNA to get in the many available options. That is why I got the AURSINC 1.5Ghz version on Amazon. Link below;
https://www.amazon.com/dp/B07Z5VY7B6?psc=1&ref=ppx_yo2ov_dt_b_product_details

But looking through this forum and other places, I learned that some versions can that some version use harmonics to reach the microwave range instead of doing it nativity
or that support different types of firmware (like the NanoVNA H-4) like described by the post below;
https://www.eevblog.com/forum/rf-microwave/nanovna-h-nanovna-h4-litevna64/msg5162697/#msg5162697
or that some versions have PC software where that have the reactance vs. frequency, Q, R-jX, like shown in the post below;
https://www.eevblog.com/forum/testgear/tiny-sa-nano-vna/msg5570661/#msg5570661
or have a very attractive UI like shown in this post below
https://www.eevblog.com/forum/rf-microwave/which-nanovna/msg4681822/#msg4681822

Anyway, after doing some more research I have locked in the LITEVNA64 on R and L Electronics, for $159, But I still have questions;

• Are there better alternatives to the LiteVNA64 that are roughly around its price and it's frequency range??
  
  
• (Important) Does this device actually reach 6.3Ghz without using some sort of harmonies? I am aware that all NanoVNAs use square waves which cause problems with harmonies but I am specifically asking if it uses harmonics in any way to extend it's frequency range
  
  
• doing some research on this forum, I've learned that the liteVNA has some problems with bandwidth, specifically when taking narrow-band measurements, what does that actually mean? If for example I'm trying to measure at specifically one gigahertz, am I not able to do that? How does this affect me in the world?
   
  
• (Important) Is there good PC software for the liteVNA that supports functions like the pictures below? are there any software specifically built for the liteVNA in the first place?
  
  
  
• Does the LiteVNA have swappable firmware for different functions or is that something only made for the H-4? If not, is the NanoVNA H-4 worth buying for both it's phase frequency analyzer functionality and it's supposed narrow-band performance below the microwave range (even if I am not particularly focused on that aspect of RF)
  
  

Anyway, if you made it this far, thank you so much for reading my post, I know I'm asking a lot of questions but all this is slightly overwhelming and I just do not know what to do

I will send this post to different but appropriate parts in this forum to try to get as much reach as possible, if that is against the rules, please inform me and I will delete the extra one! I am still new to this community and I'm not 100% aware of the do's and don't's