HPSM trial vs licensed version? What is the difference?

Hello,

Can I keep on using my trial HPSM (any latest version) by regenerating temporary license for every 60 days?

If the number of concurrent users are approx. 60 at any given time.

Is there anything that won't work with respect to HPSM after certain days?

I am interested in SD and IM module only.

Cheers...