Yes that is a known site see this link of how bad it used to be https://flic.kr/p/a5D7xZ - yes had pull seedlings if you can - will alert Mitchell Depot of need for follow-up.
Wow, to quote the URL (posted/taken on July 22, 2011):
"A recently discovered large infestation of Spanish Heath (Erica lusitanica) at Percival Hill Reserve. This environmental weed has flowers that look a bit like the native Peach Heath, but the leaves are very different. The leaves of Spanish Heath look a bit like those on native Small-leaf Parrot-Pea or the many-flowered variety of native Cryptandra, but the Spanish Heath leaves are in whorls around the stem and are very narrow - less than 1mm wide. The stems of Spanish Heath are also covered in small soft hairs. This infestation of Spanish Heath will be sprayed with selective herbicide in Spring. It is smothering a patch of native Urn Heath, native Cryptandra and Kangaroo Grass - reducing the biodiversity of 3 native plants and a number of other spring time wildflowers to one exotic plant."
I've got a few postings of this site, unfortunately the size of the infestation in 2008 and 2015 are similar in size, but not as great as shown in the 2011 image (approx. 3x larger in area).