Active Level 3
Recently I brought a s20 fe exynos variant, I was using note 8 which is 3 years old now and pretty much excited about everything FE offered( camera, 120hz, battery, ufs 3.1 and much more). 

But its been a week and I'm getting poor battery performance of 4hrs sot and I'm experiencing a lot of touch issues and was not able to pinch zoom j
Into a photo. The touch issue is bordering me too much such that the 120hz isn't giving me any feels.
To be frank my note 8 feels way too legendary in front of FE. I got too disappointed. 

Please if anyone have fixes for either of battery or the touch issue reply to this tread. It would be too helpful.
main reasons of battery drain is even you close apps but they uses ur battery and running in background unnecessary, see image and read the statement.
2nd due to huge notification enable.
for e.g ; Google has huge notification which we don't need at all see image just scroll down image and check how many notification it does have.
So do these settings to stop, which consume unnecessarily.

1. Connection>more connections settings> disable nearby device settings

2. Location>improve accuracy >disable
A. Wifi scanning
B. Bluetooth scanning .

Besides above settings do some more settings to save more battery life and observe for next 1-2 days, it will give a noticeable difference

3. Device care>battery >power mode>select "optimised" and "adaptive power saving".

And then click on "app power management >
And enable these 2 options.
A. Adaptive battery
B. Put Unused Apps to Sleep.

4. Long press on each app specially 3rd party(LIKE FACEBOOK, YOUTUBE) and rarely used apps and also ON "GOOGLE APP" as well, then click on>app info> then go to these 3 options below on by one

A. Mobile data> allow background data usage>off

B. Battery >allow background activity >off

C. Notification >disable unnecessary notifications like promotional and unnecessary reminder notifications.

5. Go to settings >apps>search "weather" >click on settings icon right side > change "auto refresh" settings as per your requirements and disable some unnecessary reminder. ( due to auto refresh it continuously consuming battery?)

6. If you use Facebook frequently then disable "auto play video"
And if you are mostly uses mobile, on wifi connection then also disable "auto play videos" in YouTube.

7. Google >click on 3dot>usage and diagnostics >off this option.
Active Level 7
All Samsung Mobile Phone will Exynos 990 have same issue
Exynos is quite old and weak processor and
Samsung is not willing to spend any time and money to make better processors

At least if they are providing Exynos 990
Then they must tweak their software to make it compatible for the Processor

Tweaking/Modification of software is the only option to solve few issues with Exynos

However i would suggest you to use your device on medium battery optimized mode

Note 20 users has also reported same issues
However company is not willing to do anything

I am also using Samsung S20 FE
but I have seen few reddit users claim 6 to 8 hrs of sot, even a Indian YouTuber made a video with 7.5 hrs sot.
7.5 hours after minimal use
Most of the YouTuber used test/review phone
Without sim
They don't binge watch YouTube or do normal day to day use like calling, using Instagram, whatsApp whole day
YouTuber have their own daily usage phone
I understand, but I really hope this improves on time with learning patterns and may be updates. Now my 3300 mah Note 8 gives me same battery as this one.
and @Rohit9r do u think we will get access to s20 series beta program?
We will not be the part of Beta Program. Beta program is for Flagship S20 series except S20 FE. After that Beta program will be available for Note 20 series.
Got october security patch just now, hoping it offers some improvements.
Security patch will not make any difference in performance or battery life
All we can hope for an update for stability/improvement