on my 25 year old 4.5 HP HR215SXA, I bought the rear discharge kit for when i had to do extremely tall grass.
It does kind of "windrow" the grass.
Typically, I'll discharge, wait a few hours for it to dry and then go back & bag.
The grass shrinks considerably by then and you can pack a LOT more in the bag.
IF super tall/wet, just mow a narrower swath,

I had a HRB216TDA a few years ago and never had any clogging of the rear discharge. Plus, after buying the rear discharge chute, I found that it resulted in excellent distribution of clippings, even when wet. It definitely did not deposit the clippings in 'windrows' but rather spread them out over a larger area where they were able to dry faster. When I came back in a day or so to bag them up, the results were excellent.
So, if you plan to get into tall grass, you're going to need the discharge chute, which deflects the clippings to the left, away from the operator. Bagging would be a pain because of frequent emptying and mulching probably would not be possible.
You'll have better results in tall grass if its dry and you set the mower to the max. height. Max height also reduces the chance of hitting objects hidden in the grass which is one of the greatest hazards to a mower.
But I would not expect clogging in the discharge chute to be a problem under most circumstances. The rear discharge Honda mowers have a short discharge path with no obstructions that constantly increases in size. The only possible clog would be in the discharge chute which has a steel baffle in it for operator safety and of course it has a 90 degree bend, but its a big chute with a large capacity. I never managed to clog mine.

The twin-blade feature on the model you are considering will greatly reduce the size of the cut blade remnants, thus also reducing the risk of clogging. These are great machines.