This suggestion has been suggested before and I thought its a very great idea. You personally get Heatproof for yourself which negates the need to carry fire resistance potions which is the whole point of Heatproof as a rune, however once you are on horseback your horsy is vulnerable to fire so you have to stack up extra fire res pots you otherwise wouldnt need to posses. Why not allow us to spend 2 heatproof runes, 1 for ourselves and 1 for mr. Horse so heatproof doesnt feel useless if ure using a horse. I dont see why this would be a disliked suggestion as fire res pots are still massively accessible if not more than heatproof so it changes nothing in siege combat.

It would simply be more convenient if we didnt need to splash extra pots for 8 minutes but thats not even the issue imo, the real issue is ur hotbar being filled with a lot of other stuff you wouldnt need to keep there. Holding 2 guns, a sword, compass/food in left and right hand already takes up half of your hotbar ngl