Yes one of mine had them fitted but not anymore since i changed shocks. Previous owner cut swing arm gussets for clearance.(made a horrible mess of it) The shocks should be 400mm long but a little longer is ok. RM-T 250/400 shocks are a few mm under 400 which makes a difference plus they have too much shaft stroke and that combined with shorter overall length creates problems. The big 5.10 tyres scrub the air box and underside of the rear fender and depending on what size sprocket you got and if you have the original muffler, the sprocket can hit the muffler!
RM 125 T shocks have the longer lower eyes which are ok but the overall length is right on about maximum for these bikes (16.5”)
If I was you I would chop off the stock eyelets, fit some new longer bump stops, perhaps 45mm foam Ohlins bump stops, or at bare minimum some 37-39mm KYB bump stops, thread the shaft to 10 X1.00mm and use longer ohlins alloy eyes, with 22mm OD heim bearings. ( 46.5mm eyes will clear swing arm with a few mm to spare) and then use Ohlins lower spring clips which will work with the RM springs. It should turn out a pretty good job and you don’t have to butcher the original swing arm and worry about clearance problems with too much shaft stroke etc.
And if you want to get rid of those shocks then im interested and need a set of those for a project