Seems really weak to me as a starting battery. Also the quality and design of the BMS is so important for a starting battery that I would be really leery of such a cheap battery.
X2.
I run an Ionic 125ah starting battery with a 300 Pro XS and 9.9 kicker and have had zero issues.
If all you are using it for is starting a motor you will not see much advantage over sticking with a lead acid.
With respect to potential alternator damage from using lithium starting batteries, Mercury has formally approved lithiums for a variety of motors and concerns about other models/manufacturers is a bit overblown.