The spark plug tubes look somewhat beat up at the bottom, so I will replace them and carefully torque the plugs down. I would post a photo of one of the tubes but posting photos does not seem possible on this forum.

I am a little surprised at the hot spark plugs BPR2ES. I thought propane powered engines used one heat range colder plugs than petrol powered engines.

no the tubes do not need replacement every time

the only time you would need to replace those is if they were damaged from over torquing the plugs or you were having a compression leak around the plugs because of this.

as for the plugs BPR2ES?
they should do fine

I never had a problem with not replacing those tubes and some of the Toyotas I work on have over 30K hours on them. You leave the crush washers on the new plugs, but the correct number is BPR2ES (hotter)

Use Nippon Denso W9EXR-U spark plugs.
The crush washer comes with the new spark plug.
The aluminum tubes do not have to be replaced every time you change plugs.
If the area where the spark plug goes through the bottom of the tube becomes tattered looking, replace it.
The square O-ring tube seals do need replacing more often than the tubes themselves.
Toyota part numbers for the items are below and are individual parts (1 tube, 1 O-ring)
Spark plug tube.....11191-76001-71
O-ring for spark plug tube.....80430-76036-71
And always beware, never add oil to the engine while the spark plugs are out. One of our guys did that ONCE.