Going from 4.87 ofw to 4.87 hfw? (CFW non capable model)

Hi, a quick question in couple of hours im gonna go pick up ps3 slim (the model not capable of full CFW) but i have a question

If it is already on 4.87 ofw can i still go from that to 4.87 hfw and can i then install HEN?

Does HEN still work with all models on latest firmware?

Thanks in advance.