I'm going to extend some "short" loft bed legs 18". The legs are 3 1/2" square. I was going to "mortise" about a 2 3/4" square 1" deep into the loft leg and "tenon" an 1'' on the extension, then center a 1" dowel about 2" deep into each section. Glue everything together and paint. Is the mortise and tenon going overboard if I do the dowel? Or even do the dowel 3-4" deep? I'll have X bracing plus the bed frame bolted on the ends, plus a crosspiece on the bottom in the back. Solid enough with the dowels, or should I "mortise and tenon"? Thanks. Greg