If you’re going to do a lot of this, I would invest in a second transmission as a spare.
Trannys are not designed for this, and you will wear out the synchronizers, especially if you have a heavy touch on the shifter. The synchros are made out of brass or other soft metal, and whenever you use them, they drag on hard-metal cones inside the gear you’re shifting into, until they are at the same speed.
If you’re going to do this, use a very light touch, and let the shifter “drop into” the next gear, rather than trying to force it! Otherwise, you’re just grinding down your synchronizers.