Lithium ion battery CV mode
Can we eliminate CV mode and use it?

Yes.

If use like this Any battery degradation/life cycle/capacity issues?

You will be at about 70% of maximum capacity, and have a huge increase in cycle life, see the third table at https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries .
Not discharging them below, say, 20% will also increase cycle life, at the expense of usable capacity, of course.
Charging faster by increasing the CC current will probably reduce cycle life as well.