I'm interested in this 40a "smart"
Charger
It perhaps not that smart for a 30 to 40 amp charger. For long service life, if possible charge, at less than 0.5C. However most cells specify there number of charge cycled, offer in excess of 2000 cycles based on this charge rate so natural aging will perhaps end the service life before charge and discharge cycles.
With a lithium battery charger a voltage lower than 14.6 volts may/will be less stress full and prevent BMS shutdown due to cell over volts. Victron for example recommend 14,2 volts and it can be shown that voltages as low as 13.8 volts can charge to 'nearly full' without a significant increase in charge time.
The charger does not specify the float voltage or the mechanism that will determine 'full charge'.
I would not worry too much about the effect of charging when the batteries are near end of practical life. If you treat the batteries with a correct and low stress charge regime, any loss of capacity will be well into the future.
However if you charge and discharge at high currents and/or keep the battery at high charge voltages for extended time periods, and/or use and store the battery at high temperatures, then the service life could be less that two years.
For slightly more money , the Victron 30 A would in my view offer a better solution. Has the ability to fully programme, via the Bluetooth app, all charge parameters, has a last 40 charge cycle log and has a 5 year warranty
Mike