I can't reply to an individual person on this video. However,@Mark Turner, if you want to go over previously painted, wash thoroughly with Sodium Hypochlorite, Trisodium Phosphate, and soap jetted through a pressure washer, and rinse. Apply a primer depending on what paint is existing. RockCote Acrybond would be great. Go over with something like Dulux AcraTex Sponge Fine or RockCote Poly White. Paint with two coats of Dulux 955 or Weathershield, or RC Armour or Ecostyle.
Dulux and RockCote are the two best renders I have used, both bagged and acrylic.
Be careful using acrylic outside if you are inexperienced, in summer you have maximum of maybe 10minutes some days to trowel it on and float it off. Start on small walls and build up.
Acrylic render, pretty much as a rule, you can't patch it. It you have a defect, generally you will have to re-skimcoat the whole wall. Bagged render patches beautifully.
Be careful painting acrylic render too. Depending on the finish, it may have a texture and top coat similar to maybe an AeroBar, or pumice stone. Picture framing can happen really quickly and easily if you are not careful.
Painting cementitious render is easy and picture framing is rare, even on havy textures like bagging and lambs wool mitt textures.