If you can try a couple it would be great...if not try a four inch with adjustable weight system...[I have several 4 "Axions on my bows like that]
they do make a differance in noise, stability in pin float, and can assist with follow thru...they really do make a differance...a really long or heavy one can be outstanding on the range ...but a hinderance in the field...
For a wrist sling...anything that will catch the bow if you drop it...something that was crucial with older bows as they would litterly jump out of a relaxed grip...
the sling should be very loose on wrist and there for confidence in a relaxed shot and follow thru...too tight and it can slingshot ot torque the bow making shots worst...
They dont have to comfortable as they are loose...use a material that allows easy and fast access or release to bow grip...
the Para cord braided are awesome as they are tuff, last forever..are stiff and flexible to allow fast access and reasonably inexpensive...they can be held on via Stabilizer, a simple bolt or in a Riser build in attachment like the APA bows...
Proper grip with a combination of sling and stabilizer make make a huge differance in groups and accuracy...
Neil