We sailed on a sloop that hoisted a solent jib on the regular forestay when the wind piped up (25kts).
A Solent jib is by definition NOT hoisted on the forestay, but on a separate stay whose head
is near the forestay's and whose deck
termination is somewhat aft of that of the forestay.
So, not sure what you are talking about.
In the distant past, long before furling sails
, we tried out slab reefing jibs. Never found them satisfactory, for containing the bunt of the sail proved nigh impossible for more than very s hort intervals, and sail shape wasn't good either. Further, setting the reef on a pitching fordeck was damn hard and quite scary. In the long run, changing headsails was a better method of reducing sail area.