I've added a note about a correction to an abbreviated word in my reply 3.
Wow, thank you so much for deciphering that handwriting! I couldn't wrap my head around it. I noticed on the margin that it says the deed was registered on 29th January 1750. Were Robert and Michael alive when the deed was first made in 1723 but died before it was registered?
I wasn't making much headway until I realised that what I first thought were individual long words were actually strings of short words. It's as if the scribe couldn't spare a millisecond to raise his quill from the paper in between words. Another thing is that his use of capital letters was inconsistent. The combined 2 idiosyncrasies caused me to attempt to transcribe what I thought was the name of another place in County Fermanagh beginning with T before it dawned on me it wasn't a place called Tohaveand but part of the phrase "to have and to hold".

You would have been led astray and then be asking people where the place was.
I saw the note in the margin about registration in 1750. Someone who knows more about leasehold law may be able to explain.
As I understand the deed, providing I interpreted abbreviations correctly, William Somervill and a Michael Hirst were deceased when the deed was written in 1723/4 and their sons were being added to names on the lease, perhaps in their steads. There may have been more than 1 Michael Hirst named in the deed, perhaps father & son. It was customary to add the name of a child or young person to the list of names on a lease as a way of extending the number of years the lease remained in force. That was a gamble as, in a period of high infant mortality, a named child might not survive to inherit the lease.
The 1750 registration may have been when one of the boys named in the 1723/4 document succeeded to the property. They would have been men in their thirties then, if they had survived.
Fermanagh is in the province of Ulster. There were customary leasehold rights in Ulster superior to leasehold rights in the other 3 provinces of Ireland.