6f5 over partially sunk earthpress grass grids?!

[marmic]

Long shot this - hoping there may be somebody out there who has tried something similar? Or any educated opinions and ideas please?!  We installed some earthpress grass grids about 4 years ago (vibrating roller to push in - link below) - looks like being marketed differently now.   Tracks to park/drive on, walk, and for horses. We are on heavy clay and some areas have over time sunk a little - or the grass and mud risen, whichever way you look at it same difference! (areas on a very slight gradient and less wet still pretty good, but still bit muddy. fortunately this is the horse bit 🙂).  Not sunk deep and still stable but no longer practical to drive on with road tyres! And walking on requires wellies at the moment.  I'm thinking maybe run some gravel boards to edges and add a layer of 6f5 or similar. Thinking is the grids will work as a base and the aggegate will lock into the grids.  Or will it make a bigger problem and go through and sink pushing up more mud, and/or push the grid down?  Or maybe lay a woven geotextile membrane straight onto the muddy grids first?  I can't decide what I think and going round in circles! 🤪 Want to avoid an expensive mess!  The plan was for more grid extending a track but I'm now thinking we'll probably dig 2 trenches with french drains as wheel tracks - we can run them downhill fortunately. Then maybe grids over that (albeit if we do it well probably not necessary).  Hope there are some opinions, ideas, and/or experiences out there please 🤞