Ok let's do a reality check: what do you mean by "glucose syrup"?
There are quite a few variants made on rice, potatoes or maize starch which all have different fermentation profiles because some are reduced to simple sugars by the process, but some are left with more complex carbs. They don't all ferment out completely. I would guess your "rice glucose syrup" is actually maltose syrup which is available from Asian stores for use with glazing Peking duck whatever. I actually use this and it does add some body. CUB use maltose syrups in mid strength beers to avoid them becoming too thin.
I notice that some of the cheaper Dutch beers such as Hollandia and Hooten now declare "maltose" which I would suspect is very similar product to the Chinese Maltose syrup product.
"Glucose syrup" is a bit of a minefield unless you can determine how fermentable it is. From experience I have learned how to use the Chinese Maltose Syrup which of course comes from rice.
Now in your recipe you say "500 ml rice malt syrup OR glucose. Glucose itself is actually Dextrose which will ferment right out and thin the beer, quite the opposite of the rice product so I wouldn't use it to achieve the ends you are looking for.
If looking to improve "smoothness" I'd go for the Chinese product if you can get it.