when I use safepal wallet (not recommended)
Side question: why do you use it if it's not recommended?
or something I have not learned yet?
My advice: get a wallet that supports Coin Control. If possible, select an input that doesn't require any change.
That being said: if you have 0.0016 Bitcoin in your wallet, you should probably not spend it at all if fees take up 20% of that amount. Just
wait for better times.
I guess it depends on the time zones, the traffic varies.
You are correct. I noticed ViaBTC's accelerator availability indeed varies during the day.