Does the card cover Instavolt and Polar as well as ChargPlaceScotland chargers?
The card definitely doesn't cover Instavolt, but that's no big deal as Instavolt take contactless bank cards and you don't need any kind of scheme membership there.
I fairly sure Polar don't take CPS cards, but I am not 100% certain, as this is mired in politics.
CPS is an organ of the Scottish Government, which has (wisely IMO) retained ownership of the 'brand'. Compare with England where similar funding gave away the brand ownership to private bidders who either frittered it away wastefully (Source East) or sold it out from under them (CYC).
The actual operations of CPS are subcontracted to CYC, and the CPS card is in effect a CYC card with different branding on it - both cards work equivalently both in England and Scotland. Shortly after the contract was renewed in 2016, Chargemaster (Polar) bought CYC.
In England, they immediately enabled use of Polar cards on CYC points but not CYC cards on Polar points - evidently with a view to pushing customers onto their monthly subscription product for the Polar card (their profits from the CYC locations come from the fees paid by the site owner rather than the end user, so this lets them earn both ways round).
In Scotland, CPS refused to allow that so Polar cards are not accepted on CPS points.
Chargemaster/Polar have always avoided roaming agreements on their network (again, driving subscriptions for their native cards); indeed CYC used to have a roaming agreement with TheNewMotion but Chargemaster terminated it soon after the takeover.